The estrous cycle is regulated by hormones. The normal pattern shows a follicle developing on the ovary and producing estrogen. Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH) are produced by the pituitary gland. These two hormones help mature the follicle and cause it to rupture. A corpus leteum (c.l.) develops in the bed of the ruptured follicle and produces progesterone which prepares the uterus for pregnancy. If conception has not occurred, the uterus will produce a prostaglandin which causes regression of the c.l. and will then allow the next cycle to take place. If conception has occurred, the prostaglandin will not be produced and the c.l. will persist and help maintain the pregnancy. Goats require c.l. for the entire length of the pregnancy. Occasionally the planned hormonal control will malfunction. A common occurrence is the â€œfive-day heat.â€ A doe will come into season and stand for the buck normally. We carefully enter the dates on the calendar and start planning for our babies in 5 months. But 5 days later, the doe is back in season and standing once again for the buck. He is happy and so is she, but what does this do to our 5 month plans? Apparently the follicle produced with the first heat did not rupture (ovulate). But since it was ripe, it took only a few days for the hormones to build back up and prepare for ovulation once again. The majority of does will ovulate at the five-day heat and you should adjust your calendar accordingly. There is almost no chance that she would have ovulated at the first heat. Taken from Pygmy Goats Management and veterinary care by Lorrie Boldrick and Lydia Hale This is true for all goats.