Does the amount of estrogen in birth control pills (ex. low, high or moderate levels) have any effect on protection against pregnancy? For example, is it better to take a birth control pill with a higher level of estrogen than one of the newer "low dose" ones? Will the protection be the same?

My bf has a small penis. He is overweight and his penis is hidden somewhat. The tip sticks out but if you move the flap of skin around the shaft you can see it's longer down there. Is there anything to fix that? How do we have sex?