i doubt you are pregnant. do u know how hard it is to get pregnant? i know u must hear left and right about how teens and people on maury povich show get pregnant just by staring at a guy... but seriously, having ONE unprotected sex--the chances are not too high... unless you were ovulating. and what i mean by ovulating is, how far are you away from the last time you had your period?

technically speaking, they say that you can even get pregnant if the guy didn't even penetrate you, but his sperm was all over your outer area. but i'm sure the chances there are even MORE INFINITISMAL.

in any case, you could go to see if your doctor for that morning after pill because it works within 72 hours (3 days.) and since you had your sex on friday night, it's only sunday, so hurry up and go to an emergency dept or an open clinic!