I'm not sure if that is normal when starting yazmin birth control. I am on desogen and before that mircette. I didn't have what you are describing. I started my period on the 4th week of the pack and everything was fine. Your body could just be adjusting to the hormones. You should probably call your doctor and describe these symptoms. They can tell you whether that is a normal reaction.

On the other hand, I DO know that BC pills won't hurt your baby. Let's just say you are pregnant. As soon as you find out, stop your birth control pills and everything will be okay. I know they don't have any adverse effect.

Wishing you all the best.

-crimsonrose