Off bc

I got off of my hormonal bc around the 20th of November and had unprotected sex on the 23rd he did not ejaculate and I took the after pill w in 24 hours just in case. I had been cramping like I was gonna start my period before we did it and I started my period less than a week but it only last 3 days and I’m still cramping like I’m on it could that mean I’m pregnant or my body is just getting use to being off the pill???