4th IUI seems to be BFN

I got pregnant naturally 3 years ago after 4 years trying to conceive and 2 unsuccessful IUI, super excited and lost my baby @8weeks We were devastated, horrible experience. Since the beginning we agreed to try maximum 3 IUI, after our loss I didn’t want to try again and my husband insisted so I only tried the last chance for him and bang got pregnant, my kid is 2 years now. 8 months ago I got pregnant naturally super excited again and lost the baby @8 weeks. Now we want to try 3 IUI for baby #2 and took the 1st chance apr 15. Tomorrow is due AF and I have been testing April 25, 26 and 27 and all 3 BFN (clear blue digital). I am still waiting and hoping that AF doesn’t show up tomorrow and next Monday I get a positive but I am cramping (PMS). If I get my period tomorrow I will try again next month. Infertility sucks.