I had sex Friday two weeks ago and my period was dued that weekend. I got my period on that Sunday. Usually I have heavy flows but this time I would not have enough blood to fit on a pantliner. Plus my blood was brown which its usually red. I have lower back pain at times and my stomach hurts occasionally. After I eat sometimes I get this feeling I might throw up( my mouth gets watery and I can taste throw up in my thoart). And I have been gassy. I need help I don't know what could be wrong.

First step: buy a pregnancy test. Second step depends on the results of your first step. If it comes out negative then please remember anything can make your period eregulate, stress, medication, even change in diets or workouts. If the problem last more then a few periods (months) I'd make a appointment with a OB/Gyn. Good luck :)