Please help.

I did my first <a href="https://glowing.com/glow-fertility-program">IUI</a> on Feb 14th (unmedicated) but My period started yesterday.. usually my period starts off at full speed heavy bleeding for about 3 days then lightens up. This time I am hardly even spotting. Not even enough to show up on a pad yet. Just enough that I can notice when I use the restroom. Is this because of the progesterone?? My body has never dont this before. Also, I don’t ever spot during my cycle.

Thanks!