Maybe pregnant? I don't know 😫

Hello this is my first time ever posting anything but I'm a little nervous. I had unprotected sex about 2 weeks ago and then again about 2 days ago. The difference being I started taking penicillin for strep throat on Valentine's Day. Yesterday was my first "period day" which nothing ever happens. Today however I normal wake up to cramps and light bleeding of old blood and have had nothing but a muscle cramp (similar to after working out) on my left side. The day is still young and I do take micrgestin fe and have been for a year now, but I need some piece of mind. My fiancé leaves for Florida for 5 months in May and we are getting married in October. Help!