Had my IUI done 4 days bak. I didn't had any cramps/discomfort aftr IUI. But some times I feel a tingly/itchy feeling near uterus & it goes away. Reason?

Not unusual. The IUD is a foreign substance in the uterine canal. Such discomfort is not unusual in first week or so. Give it time and if it does not resolve to your satisfaction go to the clinic that inserted the IUD for checkup.