This happened the sec week after my period as well

Of course you do know I am sure Plan B is not for regular use and can cause many of its own problems if taken too often.
It is for unplanned. If you are going to have regular sex you need to get on a standard birth control.

With that said, Plan B of course as you know is not 100 percent effective. So even taking it will not always work. Also the longer you wait to take it after having sex, the less effective it is.

So to answer your question, while a small chance, yes there is a chance.

If you took the emergancy pill anytime in the 72 hour after unprotected sex there is still a risk but its very low the sooner the pill was taken the better as its more effective