A 25-Year-Old G0 P0 Female Presents for Evaluation of Missed

A 25-year-old G0 P0 female presents for evaluation of missed menses. Her LMP was 4 months ago. Her cycles have been irregular over the last 3 years, ranging in length from 40-60 days. She is sexually active in a monogamous relationship with one male partner for the past 2 years. They use the withdrawal method for contraception; the patient states that the method has been effective, and she denies any symptoms of pregnancy. Other history is not contributory. Her physical exam is unremarkable and a pregnancy test is negative. She does not desire pregnancy now. Her initial laboratory tests are normal, including a positive progesterone challenge test. Your assessment is anovulation. Which of the following therapeutic options would be the most appropriate for this patient?

A) Premarin 0.625 mg q day X 21 days of the month, Provera 10 mg on days 16-21
B) Any low-dose monophasic combined oral contraceptive, 1 pill q day, monthly
C) Medroxyprogesterone acetate 10 mg q day, first 10 days of the month
D) Estradiol 2 mg q day X 21 days followed by micronized progesterone X 12-14 days