Irregular menstrual cycle. Are normal.

I had irregular menstrual period, from 2 to 3 years.6 month before i had miscarriage in 5th month of pregnancy due to hormonal disbalance.after this only 2 month i had menstruation then i consult doctor and discuss about my delayed period from 3 months.they suggest medicine and i had period but only i had 2 days menstrual flow..i again discuss with my doctor he told due overweight this irregularities occur...as my height is 5 ft and wt 62 so bmi is more....so doctor suggested not to concive till i reduce 10% of my body weight...so i started excersice n reduces my 4 kg weight..but then also my period is irregular....i m soo much worried that whether i can get pregnant or i had some infertility problem like polycystic syndrome etc...all my thyroid tests and Overy tests are normal...