Fertility & pregnancy glossary

Key definitions for ovulation, conception, and pregnancy tracking.

Ovulation

Release of an egg from the ovary, usually mid-cycle. The most fertile time of the menstrual cycle.

A few days around ovulation when conception is possible.

Estimated delivery date, typically 40 gestational weeks (280 days from the first day of last period).

Medical counting starts on the first day of your last period, before conception.

Pregnancy is divided into 3 trimesters: T1 (1–13), T2 (14–27), T3 (28–40).

In vitro fertilization: egg is fertilized in a lab, then embryo is transferred to the uterus.

Cervical secretion that changes texture around ovulation (clearer and stretchier).

Luteinizing hormone; its surge triggers ovulation about 24–36 hours later.