8 Days Post IUI AF like cramping

Hi! First time poster. I am currently 8 days post IUI (first one ever) and am having AF like cramps that started this morning. I was on Clomid, took a trigger shot, and am on progesterone suppositories. I usually have incredibly tender breasts along with my monthly visitor but no sign of that yet. I irrationally took a test earlier today and got a BFN, but I know it is still somewhat early. Not sure if AF is planning an early arrival or if my cramps are normal at this point. I have read multiple boards but have yet to find anything useful (in terms of easing my nerves). Anyone else out there have similar symptoms? And better yet, ended up with a BFP? Thank you!!