They do say that Pamprin covers all symptoms. I'd give that a try.

Usually, the first couple of days are the most uncomfortable. In my opinion, the diarrhea, stomach ache, and nausea could certainly be from menses. The vomiting doesn't quite go (with my experience), but some people have a strong reflex to vomit (ie: some people even fight the urge to vomit when toothbrushing).

If your symptoms lasted more than 2 days, chances are that you had a stomach bug and it wasn't the menstruation causing the misery. Next month, see what happens, and you'll know what to expect & learn how to cope with the "fun".

Best wishes to you!