What do cramps feel like?

This probably seems like a very silly question, but I'm on my 5th period ever and I have some really bad pains, but I'm not sure if it's a stomachache or cramps. Heheh. I had a very heavy flow today and I felt terrible. I have this twisty stomachache feeling down there, but it's focused on my right side. I had this but much worse the whole area yesterday. Thank you for answering my probably odd question!