??Letrozole with Gonal F & Ovidrel ??

I need stories any info or input anyone has. Ive did 2 cycles of letrozole(2.5-5mg) an got pregnant and had a miscarriage. Then did 7.5 mg. Im now on my 5th cycle an my doctor says my follicles are small and not growing fast enough im supposed to take 2.5 mg letrozole on days 5 thru 9 and on day im supposed to take the gonal f shot 75iui and an ultrasound. Has anyone had any success and how long did it take? Ive been ttc for 2 years now and i really hoping this works.