I had unprotected sex then the day straight after i got my period and it was a regular heavy period does that mean i didnt get pregnant during the sex??

Based on the information provided, it is highly unlikely that you got pregnant during the sexual encounter if you had a regular and heavy period the day after. This is because menstruation is a sign that the uterus is shedding its lining, which occurs when there is no fertilized egg to implant in the uterus. However, it is still important to note that there is always a small chance of pregnancy