7.5 mg of Letrozole not working

G

Has anyone had problems with their follicle size taking 7.5 mg of Letrozole. I am taking 2000 mg of metformin and 7.5 mg letrozole and I my follicles still don't grow. My doctor said the next round we need to try daily injectables. Has anyone else experienced this? What was your experience with daily injectables?