Stupid mistake

I had unprotected sex last Thursday my first time too my boyfriends penis never went fully inside me because I wasn’t use to that since it was my first time and he only did like ten thrusts before I told him to stop because I knew it was unprotected and I’m just so scared to be pregnant he never came and he said he would’ve know if he was even close but yea It was a stupid mistake on my end I’m just scared I’m supposed to start my period in four days. sorry for the rant I just needed to say it