Trying & Testing Timeline
Start with the cycle or timing record you actually have. One interaction shows every supported ovulation, fertile-window, expected-period, and home pregnancy-test timing reference that record can provide.
Calendar-estimated ovulation is not confirmed ovulation, and a pregnancy-test date or window is a timing reference—not pregnancy probability, diagnosis, or a guaranteed result.
Transparent, browser-based pregnancy and preconception calculators and reference tools for educational use.
One record, only the outputs it can support
| Record you have | Supported outputs | What is not inferred |
|---|---|---|
| LMP + usual cycle | Estimated fertile window, ovulation, expected period, test reference, today context | Confirmed ovulation or pregnancy probability |
| Expected period | Home-test reference and early-negative context | Ovulation, conception, or implantation |
| Well-supported ovulation | General 12–15 DPO urine-hCG reference window | Conception date or hCG concentration |
| Current DPO | Derived calendar reference and testing window | Ovulation confirmation or individual probability |
| Recent relevant sex date | Conservative 21-day test reference | Conception, implantation, or contraception effectiveness |
How to read the provenance labels
- USER-ENTERED identifies the record or number you supplied.
- DERIVED identifies direct date arithmetic from that record.
- APPROXIMATE identifies a calendar estimate that can differ from an individual biological event.
The labels prevent a cycle estimate, an entered record, and a biological event from being presented with the same certainty.
Why an early negative may not settle the question
Home urine tests detect hCG, not intercourse, ovulation, fertilization, or implantation. Testing before the expected period or before the applicable reference timing can produce a negative result because urine hCG may not yet be detectable.
Follow the instructions and reading window for the specific test. A missing control indicator means the test is invalid, not negative. A positive result does not establish pregnancy location, viability, gestational age, or a due date.
Calendar estimates, LH, mucus, and temperature answer different questions
A cycle-length model estimates timing; it cannot confirm ovulation. An LH/OPK result may suggest that ovulation is approaching, cervical mucus can provide current-cycle context, and a basal-temperature shift is mainly retrospective. The tool does not combine these different signals into a fertility score.
Do not use the highlighted dates as proof of safe or unsafe days for contraception. No individual pregnancy probability is calculated.
Treatment, recent pregnancy, and time-sensitive contraception questions
Fertility medicines containing hCG can affect a home pregnancy-test result; follow the testing schedule from the fertility clinic. After delivery, miscarriage, or abortion, residual hCG may also complicate interpretation.
If recent sex or contraception failure creates an urgent pregnancy-prevention question, use appropriate local emergency-contraception guidance or a qualified healthcare professional. This tool does not determine eligibility, recommend a product or dose, or delay time-sensitive care.
Official sources
Each source is mapped to the specific timing or boundary statement it supports. These sources do not review, sponsor, or endorse Pregnancy Metrics.
- ASRM — Optimizing Natural Fertility
Supports the six-day fertile-window definition, higher-fertility timing near ovulation, cycle variability, and the limits of calendar and app predictions.
- ACOG — Trying to Get Pregnant? Here’s When to Have Sex
Supports cycle day 1, the cycle-length-minus-14 calendar convention, and plain-language cycle timing context.
- ACOG — Fertility Awareness-Based Methods
Supports the distinction between fertility-awareness information and contraception and explains that fertile timing cannot be reduced to guaranteed safe days.
- NHS — Doing a pregnancy test
Supports testing from the first day of a missed period and the 21-day fallback after unprotected sex when the next-period date is unknown.
- Office on Women’s Health — Pregnancy tests
Supports hCG detection, instruction and control-indicator requirements, and why early testing can produce a negative result.
- FDA — Home-use pregnancy tests
Supports variation in home-test sensitivity and use, false-negative risk from early testing, and the general urine-hCG timing context after ovulation.
- MedlinePlus — Ovulation home test
Supports that an LH surge may precede ovulation while a positive home test does not make the exact ovulation date certain.
- CDC — How to be reasonably certain a patient is not pregnant
Supports limits of urine testing after recent sex or a recent pregnancy and the possibility of residual hCG.
Private by default and limited in scope
Inputs remain in ephemeral browser state. They are not placed in the URL or hash, sent to an API or server, or stored in localStorage, sessionStorage, an account, or a database. Reloading starts a new blank interaction.
For a deeper explanation of cycle signs, hCG, early negatives, and source boundaries, read the Trying, Ovulation and Pregnancy Test Timing Guide.