You very well could be in perimenopause. and since it has been 4 months since a period, that would point more to menopause, but the "rule" is one year with
out a period for it to be official.
I would recommend you do lots of research and see if sounds like what you have been experiencing.
Also, I would recommend you contact your dr in regards to the iud
and the other symptoms
. I hope you have a good dr. Those are so hard to find.