Advice? Please.

I've been on birth control the pill. & I had to have a tooth pulled, was put on antibiotics. Stopped taking it cause I know it's less effective anyways and used a condom any time I had sex. Then started back taking the pill. Could this of made me not have a period? I started my period like with the brown stuff then took bc to stop it until the next week. & it still hasn't started. Any help?