what's happening? should I worry?

To understand what is happening, you have to understand how Plan B works.

Plan B is a very strong birth control pill. It works by halting your normal hormonal cycle to try to prevent you from ovulating. After the hormones leave your body, your body must restart your cycle. There is no single predictable way this will happen. For that reason your next period or two or three can be disturbed or absent. Many women will also experience a side effect called withdrawal bleeding or spotting about 5 to 7 days after taking it. This is very likely what is causing your period now.

If you ovulated the day you had sex, or between him ejaculating inside you and about 20 hours after you took the Plan B pill, you could have conceived. The chances of ending up pregnant is however very small.

You should have used another Plan B or other birth control/protection on Feb 11. The Plan B you took on Feb 8 would not have protected you on Feb 11.

So you can see why this is emergency contraception. It is not particularly healthy for your body or your mental state. The only thing you can do is to take pregnancy tests and wait out the side effects from the delay in your cycles.

Best of luck!

Welcome to e health forum.

The bleeding changes are side effects of the emergency contraceptive pill, and not due to pregnancy.

If you were in the ovulatory phase of your cycle, and had intercourse, only then you would have chances of getting pregnant. But taking a emergency contraception in such situation would help to prevent pregnancies.

If you were outside the ovulatory phase, then there is no risk of pregnancy, but you may experience side effects due to the use of emergency contraceptives.

Some common side effects of emergency contraception include menstrual irregularities including spotting, delayed or missed periods, reduced or increased menstrual flow, change in pattern of cycles, etc.

You might have your next periods on time or slightly delayed. You do not need to panic, but just relax and be patient. These effects are short lived and resolve on their own and no treatment is needed.

I hope this helps to clear your doubts.