Should I be worried?

My cycle is nine days late. I honestly cannot remember when was the last time I had sex, I think it was around Valentine’s Day. No protection🤦🏾‍♀️, but he did not ejaculate in me from my knowledge. Sometimes my period is a few days late, but not this late. I was cramping in my right pelvic area. The cramping felt different from my normal period. So I took a pregnancy test a few days ago and it was negative. My friend says I could be stressing about things and not know it. Not sure what to do. Maybe I’m overthinking it.