Miscarriage?

I'm sexually active and I had sex on January the 18 19 and 23. After two weeks had past I was getting cramps, really bad cramps. I also felt sick a lot. I was scared I was pregnant, but didn't take a test to see if I was. I usually trust my partner to pull out. I was smoking a lot of weed. Then had more sex in feb on the 8 and 9th. I got my period early, on the 13 and on the 17th I thought stopped. Because my period only lasts 5 days. But my flow is way more heavy, than usual. It's the 21 and I'm still on my period. Please comment!!! I'm scared.