Hi there, it sounds like the answer is no, I dont think you could be pregnant, You used a condom and I am assuming it didn't break, also you have had your period after you had sex, so i would say I think you are not pregnant. :)
It doesn't sound like it. You had safe sex, which of course no birth control method is 100%. But, you got your period on time afterwards so I wouldn't think you are pregnant.