Talk to Gynecologist on Periods/pregnancy

Actually i am facing problem of late periods.11 months are completed of being month i visited doctor she put me on meteor (metformin 500 mg twice a day) ,stalezine 1 mg and m 10 days late on my periods i done pg test but it was negative.i got pink and brown discharge on 9th day when i its gone too.. Now m having cramps in lower abdomin and having back ache. Please tell me what to do in this situation. Thanks in advance.