I had my first iui(no fertility meds) done on 7/17 and began taking progesterone suppositories 7/22-7/28. To my knowledge, I have a 28 day period which lands my period on the 31st or the 1st? I don't have any cramping. The sore breasts stopped on 7/29. well this am, I am spotting, and have not tested yet. Could this be implantation or af? I heard that if I test now (if its implantattion) i would get a bfn because my hcg doesnt increase until after implantation. Please give any insight or thoughts:) and baby dust to all ttc!!