Is that what my problem is?!

I just found this site! This is exciting, and also scary. I have been having severe hot flashes, weight gain (20lbs), headaches, etc. My husband (an MD) has been telling me it was the IUD, but I haven't wanted to believe him. My doc was pretty inexperienced with these things, and I would not have even known about it (Mirena) if my sister hadn't gotten one and loved it (still does). I was looking for a non-hormone birth control, and my doc said this only had a small amount and is only released locally to help stop bleeding. Is that even possible? The bleeding is certainly less, hardly any period, fantastic, but I'm a fat pig. I've never had trouble with weight (except during the brief BC pill usage), even after 3 kids. Could this really be causing me to be fat? Also, I now have high blood pressure! Is this a side effect anyone else has experienced?