On Letrozole and trying IUI's.. missing ovulation!

Normally OPK's work for me. I ovulate regularly, normally day 12-16. Lately while trying to catch it right before I ovulate to try <a href="https://glowing.com/glow-fertility-program">IUI</a>, I go for the ultrasound today (CD12) and I've already ovulated! Blood work will confirm that later today.

So frustrating! That means I likely ovulated before day 12 which is abnormally early for me. This is the second time I've missed my ovulation.

Is it time to give up hope of trying another <a href="https://glowing.com/glow-fertility-program">IUI</a> (one attempt with no success) and move in to <a href="https://glowing.com/glow-fertility-program">IVF</a>?

Help!