Chances of being pregnant if i had protected sex (condom didn't break&he didn't come) one day before period and then my regular period came next day?

Very small chance.: You did the right thing by using contraception and the timing suggests pregnancy would be unlikely.. Nothing is foolproof, though. Since you had your period, I would relax. If you don't want to get pregnant now, you could consider adding another form of birth control. Naturally, if you miss your next period, you are one of those uncommon ones who got pregnant despite condom use.