No. It wouldnt even be enough time for your "egg" to plant into your uterus. When was the start of your last period? you will be able to tell if you were "fertile" at the time of intercourse. Are you on any other type of birth control such as the pill?
Your best bet is to go to the doctor or pharmacy and ask for the morning after pill. if i am correct, you can get it over the counter now at pharmacies only. (but you have to ask for it). I think you can take them up to 72 hours after your "oops." This will prevent the egg from planting. Hope this helps!
I am not sure they can tell that early if you are pregnant... i would say wait awhile and take a pregnancy test in about 3 weeks or so... =)