What are the likely causes, and how can I stop it? It's frustrating because it makes me look fatter than I actually am and worry that I am pregnant.

are you feeling nauseous as well? i would recommend antacids

I've just been reading about mefenamic acid, which apparently can have this side-effect, but since I feel bloated often and not only when I have my period, it doesn't seem like a likely primary cause. I don't know whether I feel nauseous any more than a normal person might.

I took the morning after pill about six weeks ago and that fucked up my body, so I have been feeling nauseous a little, though before I took the pill I didn't generally suffer from nausea. I shall go back to wikipedia and look up antacids. All I know about them is that Kurt Cobain had cherry-flavoured ones.