If you've had Mirena or if you haven't had a period for a few months..

I got off my birth control in December 2013 I had a mirena IUD and I did not have periods with it. I wanted to let my periods regulate so me and my SO could TTC. We weren't using protection after I got it out my periods were a little odd but I figured they would regulate after awhile of not having any. Well March 27th was my last period. I went to the doctor recently and had my thyroid checked thinking maybe that could be the problem because of other symptoms I was having but all the tests were normal. I'm going to make an appt with my gyno, but I'm nervous. I don't want anything to be wrong. :/ Anybody experience this after birth control?