What Causes Period Like Symptoms Without Periods After Hysterectomy?

Hi. i had operative hysteroscopy 2 months ago to remove 2 fibroids. my periods where regular but with serious pain and excessive bleeding. my period came 2 weeks after at the right time, but with very little blood, about 5mls in total. That was six weeks ago and i havent seen any period. i had serious cramps and bloating around the time it should have been, but no blood. i tested for pregnancy and it was still negative as at yesterday, but an opk had a faint positive. what do i do ? I hope to start my IUI next 2 periods so this really throws me off balance