Pregnant? (TMI)

I’m currently 2 days late for my period but I didn’t have any sex this month until about 2 weeks ago. I’m getting really bad cramps and back pain (like usual when I’m about to get my period) and I had sex yesterday, I started bleeding a little but have stopped ever since, only a little bit of bloody discharge. I also took a pregnancy test yesterday and it was negative. I’m 18 with a 2 year old already, I’m just so confused. I don’t know if the stress from worrying is delaying my period or not.