If you want to get pregnant, you need to know about ovulation. It's the release of an egg from your ovary. If you don't ovulate, you cannot get pregnant. Problems with ovulation are the main cause of female infertility. It’s a complex process. Several things have to happen in the right sequence for a woman’s body to create this special type of cell that’s ready for fertilization. What do you need to know? Here are seven important bits of information: 1. Few of your eggs actually get to ovulate. When you reached puberty, you had 300,000 to 500,000 eggs in your ovaries. There will never be more. These stored eggs are immature eggs called oocytes. Oocytes get nourishment from surrounding cells called follicles. Most follicles and oocytes will never get to be mature eggs that ovulate. The ones that don’t mature end up dying. By the time you reach the age of menopause, the follicles are gone and so are the eggs. 2. Ovulation depends on chemical messengers. Every month, one of your eggs—usually just one—gets to mature for ovulation. At the very beginning of your menstrual cycle, low estrogen levels trigger release of follicle-stimulating hormone (FSH) from your brain. FSH tells your ovaries to start preparing eggs. One of these will become the dominant follicle. The maturing egg sends out estrogen. Estrogen triggers the release of luteinizing hormone (LH). LH triggers the dominant follicle to release a mature egg. 3. The lucky egg does not have much time. The released egg lives for just 12 to 24 hours. If pregnancy is going to happen, this is the time. The egg begins to move from your ovary to your womb (uterus). To get there, the egg travels down one of your fallopian tubes. If sperm is present, it will usually find the egg as it moves down the tube. If a sperm fertilizes the egg, the fertilized egg will make it to the uterus and implant there. Implantation usually follows ovulation by 6 to 12 days. 4. Fertilization might not happen. An egg that is not fertilized dissolves. It's absorbed into your uterus. Your hormone levels will then drop, and the lining of your uterus—which has been prepared for pregnancy—will start to shed. This shedding is your menstrual period. The beginning of menstruation is also the beginning of a new menstrual cycle. Everything begins again: the hormone changes, hormone surges, selection of the egg, release of the egg and the egg’s journey to your womb. 5. Find your fertile time. Finding the time of ovulation is important for women who want to become pregnant. Your doctor will want to know if ovulation is occurring normally. You want to know when will be the best time to have sex. For most women, ovulation occurs between day 11 and day 21 of their menstrual cycle. That's a big spread. But, there are several ways to narrow it down. Ovulation causes your cervical mucus to become thinner and more fluid. Ovulation also causes a slight rise in your temperature. You can track these changes and find your fertile time. Another option is to use an ovulation kit that detects ovulation. You can buy them in the pharmacy section of your local grocery store without a prescription. It helps you narrow down the window of ovulation. 6. There are other clues to ovulation. Ovulation causes symptoms in some women. You might have slight spotting and slight cramping. You may notice breast tenderness, bloating, a more intense sense of smell, and an increased interest in sex. Aching pain in the middle of your belly is a symptom that has a special name. It's called “mittelschmerz,” which is German for “middle pain.” 7. Ovulation is the key to fertility. Most women who struggle to get pregnant have a problem with ovulation. Let your doctor know if you are not ovulating normally, have painful periods, or irregular or missed periods. Ovulation problems can be the result of your ovulation hormones being out of balance. This condition is called polycystic ovary syndrome (PCOS). PCOS is one of the more treatable causes of infertility.