Missed Period After Sex: Pregnancy Possibilities & Other Causes

A missed period after unprotected sex raises pregnancy concern, but many non-pregnancy factors can delay menstruation.

Pregnancy Likelihood

• Fertile window: ~5 days before to day of ovulation (typically day 14 of 28-day cycle).
• Sperm survive up to 5 days; egg viable 12–24 hours.
• Implantation: 6–12 days post-ovulation; hCG detectable ~10–14 days post-conception.

Confirming Pregnancy

Home pregnancy test (hCG in urine). Test after missed period for accuracy. If negative, repeat in 3–5 days.

Other Causes of Missed/Irregular Periods

• Stress (physical/emotional)
• Weight changes (loss/gain), eating disorders
• Excessive exercise
• Hormonal: PCOS, thyroid disorders, hyperprolactinemia
• Medications: hormonal contraceptives, antipsychotics, chemotherapy
• Perimenopause (40s+)
• Chronic illness

Early Pregnancy Signs (Besides Missed Period)

• Breast tenderness, fatigue, nausea, frequent urination, food aversions/cravings, mood changes.

When to See a Provider

Positive test → prenatal care. Negative test + no period × 2 cycles or concerning symptoms → evaluation for underlying cause.