Hi My Name Is Brittany. I Had Unprotected Sex Not

Hi my name is brittany. I had unprotected sex not to long ago and when he got finished he nutted on my booty. when I walked it moved also, I also have a lot of cum coming from me so when I wiped I didn't know whether it was cum or nut so is it a chancell I may be pregnant ? what medicine can I take if so?