Not sure if I fall within that group, but I had significant cramping for 2 days after the IUI and my first cycle was not successfull. I actually started the cramping the morning after my trigger, so I think it may have been cramping from extreme ovulation. I am now preparing for IUI #2 mid-October. I keep praying everyday that the second one will be the one, that's all I can hope for right now. This journey has been soo difficult.
I have had 7 IUIs and have gotten pg 3 times from it (2 viable).
The first (non viable) and second (viable) pg, my first symptoms were sore breasts and increased thirst. I also had mild but consistent heart burn.
The third time I got pg, I had absolutely no symptoms at all.. I was conviced I was not pg but I was.. :)
The 4 IUIs that I did not get pg, I really didn't feel anything at all.. same as any other cycle...