Unprotected sex?

How long should you be on the pill before having unprotected sex? I've only taken about 6 pills. One everyday around the same time and I just recently had unprotected sex a day ago. Are birth control pills so effective then? Or could I still get prregnant? Also I do know that the pill isn't 100% effective but since I've only taken it 6 times is it even more less effective? Thanks!