Wondering how many days after your period you can get pregnant? Use the calendar below to see your fertile window by day based on your cycle length and period dates.

Last Period Start

Average Cycle Length (days)

Age (optional)

Female Age

Male Age

Contraceptive (optional)

Method

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Press Calculate to see your personalized Pregnancy Chance Calendar

Month Year

Menstruation

Fertile Window

Highest Chance

Ovulation

Phase:

How Many Days After Your Period Can You Get Pregnant?

Your fertile window shifts with your cycle length. In a 28-day cycle with a five-day period, ovulation is around Day 14, so fertility often begins near Day 9—only a few days after bleeding stops. Shorter cycles shift earlier; longer cycles shift later.

Rule of thumb: earliest fertile day ≈ cycle length − 19; ovulation ≈ cycle length − 14; peak chance ≈ cycle length − 16 to −17. Examples — 26-day: earliest ~Day 7, ov ~Day 12 • 28-day: earliest ~Day 9, ov ~Day 14 • 32-day: earliest ~Day 13, ov ~Day 18.

The average cycle is about 28 days, but cycles commonly range 21–35 days.
Menstruation typically lasts 3–5 days.
Ovulation happens roughly 14 days before your next period (earlier in short cycles, later in long ones).
Sperm can survive up to five days in the reproductive tract; the egg is viable about 12–24 hours.
Your fertile window is the five days before ovulation plus the day of ovulation (six days total), with the highest chance in the two to three days just before.

Understanding Your Menstrual Cycle

Your cycle starts on Day 1 (first day of bleeding) and ends the day before your next period. These phases explain fertile timing:

Menstruation (Days 1–5)
Shedding of the uterine lining; average bleeding lasts about 3–5 days.
Follicular phase (≈ Days 1–13)
Follicles mature in preparation for ovulation.
Ovulation (≈ Day 14 in a 28-day cycle)
A mature egg is released and remains viable for 12–24 hours.
Luteal phase (≈ Days 15–28)
The lining thickens; if no pregnancy occurs, hormones fall and the next period begins.

Factors That Can Shift Your Timing

Irregular cycles, including PCOS, can make ovulation unpredictable or absent.
Stopping hormonal birth control may delay ovulation for a cycle or two.
Stress, illness, travel, and lifestyle changes can nudge ovulation earlier or later.
Tracking methods—basal body temperature, cervical mucus, and at-home LH tests—help pinpoint the window.

Bottom line

You can get pregnant from the last day of your period up to 24 hours after ovulation. The best odds are in the two days before ovulation—use the calendar above to map your personal window.

Medical disclaimer

This calculator is for general information. It does not give medical advice, a diagnosis, or a treatment plan.

The results depend on your average cycle length and the date your last period started. Cycle length can vary from one cycle to the next and your true cycle length is only known after the cycle has ended. If your next period comes earlier or later than expected, the fertile-day estimates will change.

Irregular cycles, recent changes in contraception, breastfeeding, PCOS, and other health factors can make timing less predictable.

If you have concerns about your cycle or fertility, talk to a health professional. If you think you might be pregnant, use a home pregnancy test from the first day your period is late. See how our calculators work at How it works.