IUI question

I'm going through my first IUI cycle. I did 75iu for 5 days and then my blood works showed my estrogen was way low, now they have me bumped up to 200iu for the next few days. I was feeling bloated and cramps but since starting 200iu I feel normal, almost like nothing's happening at all. Has anyone gone through IUI and not had bloating/cramping? Anyone gone through it with low estrogen?