So you normally get cramps several days ahead of AF?
Not a doc, but my personal opinion is that a 11 day LP is on the short side. Progesterone is hard to assess because it's released in pulses throughout the day, so it could be ok at one point, and too low if tested at another point. Also, progesterone could be ok at 7 dpo, but drop off precipitously later in the LP, bringing on AF. If it were me, I would ask for progesterone for your next iui, especially if you get AF early again. Hoping this is implantation cramping though...