Help! Very confused!

Ok March 4 got my iud removed with no spotting or bleeding. So the 6th had sex. Yes I had dark thick light bleeding. It was gone with in a few hours. I had my af last month the 23 to 27th. Was it just because I had my iud removed? Or is this something else? I'm have cramping/ tight feeling on my lower right. And don't have an apatite much. My doc said that I'm very fertilit. I have 2 kids already. And my so thinks I'm having early signs of pregnancy. HELP PLEASE! !! And would a test show anything?