Letrozole & false OPK+

I have pretty short cycle recently 24-25-26 days last 3 months..

This is my first cycle

IUI

and I Just finished Letrozole yesterday. Pinching sensation on my left side all day yesterday. So I decided to test opk this morning. It was positive. Way to early on CD8! Usually it’s on CD12 or 13.

So I called my fertility clinic in panic (my ultrasound is scheduled in 2 days).. they took me right away. Apparently it’s a FALSE POSITIVE! 🙄 my follicles are at 9-10-11 mm. Not mature.

I think Letrozole did that. Never happened before. How weird!

Anyone else?