Pregnancy Timeline
One supported non-IVF pregnancy-dating record resolves into every connected date, week, trimester, milestone, and around-conception result that record can support.
Pregnancy Metrics
What do you want to calculate?
Start with the task you need to complete: pregnancy dates and weeks, an IVF due date, a pregnancy weight-gain reference, or trying and home-test timing. Each calculator works on its own without an account or a saved record.
Calculate first. If a result is useful later, you can explicitly add supported information to one browser-local Pregnancy Record, then reuse it without starting over. Nothing is saved automatically.
Default interactions are ephemeral and processed in your browser. No account is required. Pregnancy Record and weight-tracker data use local browser storage only after you explicitly choose to save them.
Start from the record you have
Match the record and question before opening a workflow. Supported non-IVF pregnancy-dating records resolve in Pregnancy Timeline. Embryo-transfer, pregnancy-weight, and trying/testing records use three separate workflows with different inputs and safety boundaries.
Choose one option to see the matching path and its most important limit.
This chooser uses only the option selected on this page. It does not ask for or store calculator measurements or pregnancy dates.
Available now
4 record-based workflows, distinct responsibilities
Pregnancy Timeline handles connected non-IVF dating questions in one place. The other three workflows remain separate because they use different records, methods, and safety boundaries.
What does my pregnancy record say about dates and weeks?
Use one recorded EDD, LMP and average cycle, well-supported ovulation date, documented fertilization date, or dated pregnancy-weeks record.
Information needed
One supported pregnancy record; optionally a second record for a provenance comparison
What is my IVF due date?
Use a documented Day-3 or Day-5 embryo transfer date.
Information needed
Actual or scheduled transfer date plus a documented Day-3 or Day-5 embryo age
How much weight should I gain during pregnancy?
Use pre-pregnancy height and weight, pregnancy type, and optionally a week and current weight.
Information needed
Pre-pregnancy height and weight, pregnancy type, and optional current week and weight
When might I ovulate, and when might a pregnancy test be meaningful?
Use one LMP-and-cycle, expected-period, ovulation, DPO, or recent-sex record to see every timing reference that record can support.
Information needed
LMP and usual cycle, expected period, ovulation date, current DPO, or most recent relevant sex date
Optional continuity
Save useful results without starting over next time
Pregnancy Tracker is the optional browser-local workspace behind the calculators. It maintains one Pregnancy Record with dating provenance, an explicitly selected timeline basis, meaningful history, appointments, notes, and supported measurements. Tracking and planning modules remain secondary organizers and do not interpret symptoms, movement, contractions, or care decisions.
Illustrative saved record — not personal data
RECORDED
Care-team EDD
USER-ENTERED + DERIVED
LMP-based estimate
CURRENT TIMELINE BASIS
Explicitly selected record
Saved records remain visible as separate evidence. Pregnancy Metrics does not average dates, silently replace history, or choose a medically correct record.
Not sure which one fits the information you have? Use the information-first selection table.
Choose by the information you have
Do not choose a calculator only because its result sounds familiar. Start with the information you can verify, then choose the question you need answered.
| Information you have | Question you need answered | Start with | Important boundary |
|---|---|---|---|
| First day of a reliable last period | When is the estimated due date? | Pregnancy Timeline Calculator | The 280-day model assumes the last-period date is usable for dating |
| First day of a reliable last period | How many weeks and days pregnant? | Pregnancy Timeline Calculator | Pregnancy weeks use the obstetric calendar, not fetal age |
| Current due date in the pregnancy record | How many weeks pregnant on a date? | Pregnancy Timeline Calculator | Use the current recorded due date rather than averaging older dates |
| Current due date in the pregnancy record | About when might conception have occurred? | Pregnancy Timeline Calculator | The output is an “around” calendar estimate, not an exact biological timestamp |
| Documented ovulation or fertilization date | When is the estimated due date? | Pregnancy Timeline Calculator | Use only a well-supported or documented date |
| Exact weeks and additional days recorded on a specific date | About when might conception have occurred? | Pregnancy Timeline Calculator | Keep weeks, days, and record date from the same record |
| Day-3 or Day-5 embryo transfer record | What is the IVF due date? | IVF Due Date Calculator | Use the transfer date, not an earlier retrieval date |
| Only an intercourse date, positive test date, retrieval date, or an unknown embryo day | Which result should I calculate? | First obtain the appropriate pregnancy or transfer record | These dates cannot safely substitute for the supported inputs |
| Pre-pregnancy height and weight | What weight-gain range is a guideline reference? | Pregnancy Weight Gain Calculator | Guideline-based reference, not a personal medical target |
| First day of last period plus usual cycle length | When might I ovulate, and when might testing be meaningful? | Trying & Testing Timeline | Cycle dates are approximate; the result cannot confirm ovulation, pregnancy, or safe days for contraception |
| Expected period, ovulation/DPO, or recent relevant sex date | When might a home pregnancy test be meaningful? | Trying & Testing Timeline | A calendar timing reference is not a guarantee, diagnosis, or pregnancy-probability estimate |
One supported pregnancy record can answer connected dating questions in the same timeline. The output still labels an established or entered record differently from a derived date or an approximate conception date.
Why the four workflows stay distinct
IVF Transfer Dating
A clinic-confirmed Day-3 or Day-5 embryo age and transfer date use a treatment-record method rather than an ordinary menstrual-cycle estimate.
Trying & Testing
One cycle or timing record resolves into every supported fertile-window, ovulation, expected-period, and home-test timing reference without claiming confirmation or probability.
Pregnancy Weight
Pre-pregnancy measurements and an explicit pregnancy type produce a published-reference result, an official-resource handoff, and optional local history rather than a dating calculation.
Keeping the four workflows distinct prevents unrelated records from being silently combined while avoiding repeated entry for outputs that genuinely belong to one record.
Two fixed examples show why the records must stay separate
Ordinary pregnancy-calendar example
- First day of last period: January 1, 2024
- Calendar conception estimate: Around January 15, 2024
- Pregnancy age on March 1, 2024: 8w4d
- Estimated due date: October 7, 2024
These values describe one fixed calendar timeline through several different questions. They do not prove the exact day of ovulation, fertilization, intercourse, or implantation.
IVF transfer-record example
- Day-5 blastocyst transfer: March 1, 2024
- Pregnancy-calendar age on transfer date: 2w5d
- Due-date rule: transfer date + 261 days
- Estimated IVF due date: November 17, 2024
This second example uses a documented embryo-transfer record. It must not be combined with the last-period dates from the first example.
The examples are educational calendar demonstrations. Use the dates documented for the actual pregnancy or treatment cycle.
What the workflows add beyond a single number
One record → every supported result
Pregnancy Timeline and Trying & Testing return the connected results supported by one record, without requiring the same input on several pages.
Provenance, not just a number
Results distinguish recorded, user-entered, derived, approximate, and published-reference values where those labels apply.
Records are not silently merged
Pregnancy Timeline can compare two records, but it does not average them, choose the clinically correct one, or perform redating.
Unsupported information fails closed
The workflows do not guess an embryo day, invent ovulation confirmation or pregnancy probability, or create an unsupported weekly Weight “on-track” band.
Privacy is concrete
Default records remain ephemeral browser state. Weight history is stored in this browser only after explicit opt-in; no account is required.
Methods and limits stay visible
Each result exposes its calculation or reference path and states what it cannot establish, including exact biological timing, probability, diagnosis, treatment, or delivery timing.
How to interpret a result
The same calendar date can have different meanings depending on whether it is an input, an estimated output, or a date already established in a pregnancy record.
- A due date is an estimate, not a promised delivery day.
- Pregnancy weeks follow the record or date the user entered.
- A conception result is an “around” calendar estimate, not confirmation of fertilization or intercourse.
- IVF results depend on the correct embryo day and transfer date.
- Pregnancy-test timing is a general timing reference, not pregnancy confirmation or probability. A positive result does not establish viability, pregnancy location, or a due date.
- Ovulation timing is a calendar estimate, not confirmation of ovulation, a pregnancy-probability calculation, or a contraception method.
- Weight gain is a guideline total-range and current-change reference, not a personal target, weekly classification, or diagnosis.
- A pregnancy record and early ultrasound can provide information a date-only calculator cannot evaluate.
When a calculator result differs from the current record used by the fertility clinic or prenatal care team, do not average the dates. Use the established record for care and ask the care team about the discrepancy.
How the site is maintained
Formula sources, assumptions, and update practices are documented in the methodology and editorial and methodology review. Pregnancy Metrics does not fabricate hospital, clinician, or society endorsements, and does not currently have external clinician certification.
Plain-language guides explain the methods, evidence, interpretation, and limits behind the calculators without requiring you to enter calculator inputs.
Review the privacy notice and medical disclaimer, or email support@pregnancymetrics.com with a correction or accessibility concern.
What “reviewed” means on this site
Pregnancy Metrics reviews formula definitions, source claims, supported inputs, date arithmetic, edge cases, result wording, and tests. The site does not currently claim external clinician certification.
Where formula details live
Calculator pages explain the result-specific rule and sources. The Methodology documents shared constants, date-only arithmetic, boundaries, and update practices.
Current scope
Pregnancy Metrics currently provides educational pregnancy and preconception calculators and reference tools for pregnancy dating and dates, pregnancy weeks, IVF transfer dating, ovulation timing, home pregnancy-test timing, and pregnancy weight-gain references and tracking. It does not provide fertility diagnosis, fertility-success prediction, symptom checking, treatment, fetal-growth services, pregnancy viability assessment, fetal wellbeing assessment, medication or treatment recommendations, emergency triage, or obstetric decisions.
The site’s current focus is intentionally narrow: pregnancy dating, pregnancy-calendar interpretation, ovulation timing, home pregnancy-test timing, and pregnancy weight-gain reference calculations and tracking from supported information.
It does not attempt to become a general pregnancy symptom, diagnosis, treatment, medication, fertility-success, fetal-growth, or emergency-triage service.