If it was unprotected u always have a.chance of pregnancy but these r signs of pms if ur not using birth control please do so this isn't a worry
It's highly doubtful you're pregnant if you had sex close to your period. Most women don't ovulate close to their periods, so many things can cause an irregular period, stds, stress, infections, weight/diet change etc. And, assuming you're a teen, since you're in the teen pregnancy forum, teen cycles are usually irregular. So, I highly doubt you're pregnant, however, if you're having unprotected sex, you need to look into some form of birth control, babies are hard work. Good luck!