All women, irrespective of the length of their cycle, should start ovulating about fourteen days before the next menstruation. If shorter, there is insufficient time for the endometrium to be readied for the embryo to implant, this is known as a defective luteal phase. If the corpus luteum does not make sufficient progesterone during these fourteen days, it will also result in a defective luteal phase. It appears to be a problem found in many women now and could well be due to the large amounts of oestrogen in the environment. please cont. to read...
http://www.progesteronetherapy.com/faq-conception.html
....folic acid deficiency can negatively impact the pituitary and hypothalamus glands which are sources for your fertility hormones.