Trying to conceive with pcod.

My obgyn prescribed Metformin with breakfast for 1st week, with breakfast & dinner for 2nd week and then with all three meals for further weeks. Before that I started taking Myo inositol and Dchiro inositol along with folic acid ( now switched to prenatals). Doctor advised letrozole from day 3 to Day 7 . But this is first time my periods are almost very less than earlier. Today is my 2nd day of cycle, I am feeling like it's my 5th day. No period cramps, not lower belly or back pain, no heavy bleeding, no clots. In short period flow is not coming openly. Is it normal after taking metformin? . Previously I used to get brown discharge before actual periods, this time no such discharge. I am confused and bit scared also. Should I take letrozole tomorrow being my 3rd day of cycle. Please help. Thanks.