Is it my period?

So I had unprotected sex on the 6th Febuary, and he ejaculated in me. I didn't manage to get the morning after pill so I was just hoping and praying that I didn't get pregnant. On the 9th I started a new pill, two days after that I started spotting for 2days but put it down to starting the pill. My next period was due on the 25th and its normally always right however the doctor did told me I wouldn't have my period for a while now, yet on the 18th I had really bad cramping and started what seemed like my period, but unlike my normal period I didn't have an tender breasts, nausea, Back ache or acne and its day 2 now and there's not even close to what I would normally have on the second day, I'm sure it's just the change in pill but I'm just wondering wether I could actually be pregnant, hope one of you ladies can help...đź’•