I am 26 and have the Mirena going on 3 years. I bled for 3 months after getting it put in (it was put in to stop the bleeding so your experience may vary, since I was going on a 3 month long period beforehand) It hurt REALLY bad to put in since I have never had children. But it only lasts like 10 seconds twice. One time for the insertion device and one time for the mirena insertion. Ever since the bleeding stopped at 3 months I have had hardly any bleeding, and occasionally spot lately but other than that no period. I did not have any side effects other than some cramping afterwards, but that was minimal. The hormones don't mess with your meds, they don't affect mine. It's a really low dose of the hormones anyway. Good luck.