Side effects of birth control pills

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Question
Doctor, me and my lover had sex and took birth control pills after 3 days, I got my period, but one thing I find strange, it usually takes only 4 to 5 days but now it's not over yet, so I can what's wrong?
Tran Thi Trang (2000)
Answer
The length of a cycle is usually 3-5 days, lasting from 2-7 days is also acceptable. Menstruation beyond 7-10 days is also called normal if the amount of menstrual bleeding is very small. Changes in the length of time your period ends can be a side effect of birth control pills. Depending on the type of birth control pill will have different effects. If your menstrual bleeding is still heavy by day 7 you should see your doctor.