Morning after pills and periods: Changes You May Notice

After taking an emergency contraceptive pill, your next period may come earlier or later than expected. Spotting can also occur. These changes can be unsettling, but the timing of bleeding alone cannot tell you whether the pill prevented pregnancy.

Separate a side effect from a test result

Nausea, headache, cramps, and changes in bleeding are possible after an emergency pill. Having symptoms does not prove that it worked, and having no symptoms does not prove that it failed. Avoid trying to interpret each sensation as an answer.

Record which pill you took and when, along with any vomiting and further sex. The emergency contraception choices guide explains why different products have different instructions.

Test when your period is late or unusual

Check your product leaflet for its specific advice. For example, Levonelle advises testing or contacting a clinician if the next period is more than five days late or unusually light or heavy. General emergency contraception guidance also advises testing when a period is more than seven days late. You do not have to wait for those limits if pregnancy is already a concern.

For a dependable follow up point when dates are unclear, plan a test at least twenty one days after the latest sex that could have caused pregnancy. If you test earlier because a period is late, a negative result may need repeating at that later point. Count from sex, not automatically from the day you took the pill.

The negative test guide explains what to do when bleeding still has not arrived. A clinician can help if repeated tests are negative and the change continues.

Do not wait with concerning pain

Possible pregnancy with pain on one side, shoulder tip pain, or unusual bleeding needs urgent medical advice. Sudden severe abdominal pain with marked dizziness, fainting, or collapse needs emergency care. Taking an emergency pill does not rule out pregnancy or replace assessment of these symptoms.

Prevent a new risk while waiting

Further sex can create a new pregnancy risk after an emergency pill. Follow your instructions for ongoing contraception and temporary condoms. Starting hormones may also change bleeding, so keep the planned test even if you have spotting in the meantime.