An ovulatory 35 year (no ovulation with CC) With AMH 6. D2 FSH 7.5 LH 7.5. Ovulated once with gonadotropin. But in 2nd cycle with similar doses (of highly purified FSH 150 for 5 days from d2 (as there was no follicle of 5mm) followed by 225 for another 7 days ) on d13 she  started bleeding. Her MH  4-6/35-45 days.

OH 1 FT LSCS 5 year. TSH PRL normal. PS cx vagina healthy. What is the logical explanation ?