I have had my mirena since may and I have had 2 periods a month since and between those periods I would spot constantly its now almost January and I haven't had a period since October... could I be pregnant?

Yes, you most definitely can. There is no form of birth control that is 100% effective.

In fact, I work in Labor and Delivery and one of the nurses I work with is 3 months pregnant and she had the mirena as well.

Hi, I do agree there is a chance, have you had unprotected sex? Do you feel sick? Are you putting on weight? I read the date on your question and it was poasted in December, so have you found out what's wrong yet? I sort of have the oppsite issue I have had my mirena for over a year every thing was normal until my pieriods got heaveier and painful and 3 times a month I have a boyf and I have had unprotected sex but I don't have any infections so I don't know what's wrong with me either