First of all, are you on any type of birth control? If you are, then you should be absolutely fine and have nothing to worry about. If you aren't, and you didn't use a condom, then there is a chance you could be pregnant. More so from the sex you had while you were fertile. I would wait a week before taking a pregnancy test. But you can still watch out for the symptoms of sore breasts and morning sickness. Good luck.