Not ovulating

Jessika • Mommy to my baby girl in heaven ✝️💜 TTC # 2✨

I’m on 2.5 mg of letrezole . Been on and off for years and today I did my day 21 test and I didn’t O . It always has worked for me . I’m so tired I’m sick of being kicked back to the ground . Has anyone had this happen and what did they do next ? Been on it since late 2016. 1 pregnancy she passed at 20 weeks.