Late Period Calculator

Check how many days late your period is, explore physiological delay triggers, and determine the optimal day for a pregnancy test.

Check Period Delay

Enter your expected period date (or your last period date and cycle length).

Calculated on your device. Nothing is saved.

When your period was scheduled to start

Key Takeaway: A late period means ovulation occurred later than usual. Address stress and lifestyle factors before assuming a hormonal disorder.

Understanding Cycle Lateness

Your period arrives approximately 14 days after ovulation. If emotional stress, illness, or travel delayed your follicle from releasing an egg, your period will be delayed by the exact same number of days.

When to See a Doctor

Online calculators provide general estimates based on biological averages. Consult a healthcare provider (such as an OB/GYN or general practitioner) if you notice:

  • Your periods suddenly become irregular after being consistent
  • Your cycle is consistently shorter than 21 days or longer than 35 days
  • Your period bleeding lasts longer than 7 days or is unusually heavy (soaking through a pad/tampon every hour)
  • You experience severe, debilitating pelvic pain or cramping that disrupts daily life
  • You experience bleeding between periods or after intercourse
  • You are under 35 and have been trying to conceive for 12 months (or 6 months if 35+)
  • Your period has stopped completely for 90 days or more (and you are not pregnant)
Next Logical Step

Find Out When to Take a Pregnancy Test

Calculate the most reliable date to take an at-home urine pregnancy test.

Open Pregnancy Test Date Calculator

Frequently Asked Questions

Evidence-based answers to common questions about your cycle and fertility.

How many days late does a period have to be to be considered late?

A period is clinically considered late once it is 5 or more days past your expected arrival date. Minor shifts of 1 to 4 days are completely normal natural variations.

What can cause a late period besides pregnancy?

Common non-pregnancy causes include acute stress, rapid weight loss or gain, illness/fever during the follicular phase, intense new exercise routines, thyroid conditions, and emergency contraception.

Explore other free, private tools for tracking your menstrual cycle and fertility.

Pregnancy & Due Dates

Pregnancy Test Date Calculator

Find the earliest possible and most reliable dates to take a home pregnancy test based on ovulation timing or your missed period date.

Calculate now
Period & Cycle

Period Calculator for Irregular Periods

Predict your next period range and fertile window using your shortest and longest cycle lengths. Designed for irregular cycles and PCOS.

Calculate now
Pregnancy & Due Dates

Due Date Calculator

Calculate your estimated baby due date, current gestational age, trimester, and weekly milestones from your LMP, conception, or ultrasound date.

Calculate now

Medical & Scientific Sources

  1. Mayo Clinic(2023). "Missed or late periods: Reasons other than pregnancy"
Last updated: