Letrozole and cramping?

I'm curious if anyone had cramping while on letrozole?  This is my first round 5 mg days 3-7.  I'm now on day 8 and feeling all kinds of random cramping.  Seems early to be ovulating. I see the doctor in 4 days for ultra sound to determine trigger shot day.  I ovulated on my own, but never had high enough progesterone and even with supplements miscarried, so this was next step.  Have always been able to feel ovulation but this is stronger.  Could it be because of the growing follicles? Just curious if anyone's felt the same.