Hey! I just wanted to tell you that I decided to go with an IUD after my son was born, too. Before I was pregnant my period was very regular and very predictable. Since my son was born and I got the IUD, I will actually skip months. I get months like you and the opposite of you where I bled so strong it was dripping. I can't tell you for sure if it's normal, but I'm thinking.. it probably is. You have something inserted into your uterus.. things are going to change a bit. I wouldn't be too worried unless you're bleeding obsessively.. which I think they say is more than a pad an hour, or if you stop having your period all together. Other than that.. I'd just make sure to go to your gyno regularly to make sure everything's fine. Take care and I hope this helps a little!
Smiles,
E.