Suggest Treatment For Acne

I have suffered through my teens with moderate acne and my adulthood with mild acne. I have been pregnant 3 times with all boys. When I am pregnant my acne clears up almost completely. I only get minor breakout every now and then. But once the pregnancy is over I go back to having mild acne constantly. I believe my acne is hormonal. What causes this and will there be a way I can control my acne with hormonal supplements? I am also considering Mirena in the future as a birth control method. I know most women complain about breakouts during pregnancy but I am the complete opposite.