Talk to Gynecologist on Gynecology/ Conceiving Medicine

Its been 1.5 year I'm married and had miscarriage 1.2 years ago. Im taking medicines as prescribed by the doctor in various days of my cycle. The medicines prescribed are clomitab from day 2 to 6, Gonadil F , Progynova from day 7 to 11 and duphastan from day 21 to 25. Its been 10 months I'm taking medicine and my ultrasound is also normal, I have matured follicles also but not getting pregnant and gaining weight and becoming obese, even though I eat healthy and do walk also. My cycles have always been normal but since the medication the cycle is for 30 to 34 days now. I would like to know if It is harmful to take medicines for conceiving for prolonged period? Or should I stop taking it.