Can you get pregnant while on you're period & on birth control ?

Unlikely: It's unlikely that you'll ovulate in the first few days after you start bleeding. However, I do tell my patients to consider that there is no such thing as a 'safe' day. If you are taking your birth control pills as well, then that's another protection. Birth control pills when taken perfectly every day prevent about 96% of all pregnancies. So still no 100%. Best of luck.

Birth Control: If you are on birth control the goal is to prevent pregnancy. So, I am unsure what you are really asking. Is birth control effective. Yes, in general it is very effective at preventing pregnancy.