[Always *]

You wouldn't have multiple periods. You can have implantation bleeding, where some women still have a period-like event but it's not "really" a period, I don't know how to explain that better because obviously the fetus is still there. But this happens, but I have never heard of something that could be mistaken for a normal period happening more than once after a pregnancy has occurred (so it'll happen once at the beginning and no more). And then some women experience spotting (which might be more like what implantation bleeding is like cause I just can't imagine how you could pull off bleeding a lot). What ever it is she wouldn't have had 2 normal periods and not even know about it yet. The chances that she's pregnant are very very very very low by the sounds of it and I'd just try to calm down and let it go. Sex for the first time can bring up a lot of fears like this when suddenly all the risks of pregnancy or STD's really hit you but it doesn't sound like you really have anything to worry about.