Menstrual irregularities. Yes then when?

Missed period in Sep for first time, completed Meprate 5 day course, got periods after a week, TSH,sugar normal, prolactin - 50 ng, pregnancy neg. One week last day of period in Oct, got period like light bleeding continued for 8 days, took Trantas MF 3× 3 days to stop to get Ultrasound done, did pelvic ultrasound 17 days after last day of period. Ultrasound- dominant follicle left ovary (28x19mm). Started cabergoline 0.5mg course, took 1 dose on 14th Nov (once a week x 4). Got Last cycle on 13th Oct after meprate course. Missed periods again in November. Next cycle started on 8th Dec, started Novelon 21 day course from 9th Dec. Got next cycle on 4th Jan. Maintaining healthy diet and lifestyle. Should I get prolactin and Usg pelvis done again ? If yes then when? Please help