This has always mystified me. I've talked to A LOT of women who are working on fertility - trying to become pregnant - who have worked with fertility clinics. Frequently, they say the doctors don't check for hormone imbalance! This is a huge factor in whether a woman can become pregnant or not! If there is hormone imbalance, perhaps she may not be ovulating, or her luteal phase (second half of the menstrual cycle, which comes after ovulation) isn't long enough. These things can definitely hamper conception!