When to see a doctor
If your menstrual cycle is usually regular and you suddenly experience irregular periods for no apparent reason, visit your doctor. If you have recently had unprotected sex and your period is late, it could mean that you are pregnant. You should take a pregnancy test.
If the test is negative and you’ve missed two or three periods, see your doctor. You missing periods could be due to hormonal changes which may need treatment.
If you are bleeding between periods or after sex, have very heavy periods, or have periods that last longer than seven days, see your doctor.
These symptoms could be due to an infection, problems with your cervix, or rarely, cancer.
If you are under the age of 45 and your periods have stopped, or if you are over 65 and are still experiencing bleeds, seek medical help.