Triggered period cramps

I got my period today after it was late for 2 days, I did some weight training in the morning and ate some food the canteen provides. After that I had really bad stomach pain, and wanted to vomit. I never really thought of it as period cramps as I never actually gotten cramps this serious in the past few years, my friend said that something had triggered the cramps, but I have no idea what can triggered the cramps so painfully, are there any suggestions?