Can my wife get pregnant if we had sex on the first day of her period? we used a condom and i did not ejaculate inside her, the condom wasn't damaged.

Very UNlikely: Having sex during your wife's menstrual (not ovulatory) period plus with a condom isn't likely to result in pregnancy. A woman's menstrual cycle is counted by days from the onset of one bleeding period until the onset of the next bleeding period. Ovulation may occur for ~5-7 "fertile" [pregnancy likely] days in between these 2 bleeding periods. A woman can track these times on a personal calendar.