Help me!

Hello, I had my period on January 1st to the 7th. Then again on January 28th to February 3rd. I was supposed to start on February 25th. And I have not. I had protected sex three times. Each time, my partner and I never finished. Not even in the condom. I was no where near his pre cum either. I have however, been more physically active with volleyball three days a week and skateboarding. Plus with stress from my college classes. Two days before I was supposed to start my period, I experienced cramps. I have been bloated and TMI gassy with lower back pains since I was supposed to start. Sometimes it feels like I started my period but it never shows. I don't know what to do.