Ive always had regular periods, but lately there's been a lot of spotting and early starts and pain. im 20 years old & not pregnant. what's happening?

Anovulatory: If your cycle is different, the most common cause is because your ovaries do not produce an ovum, and this is called anovulatory cycle. Most women will experience anovulatory cycles (cycles in which ovulation does not occur) at some point in their lives During the first half of your cycle, your estrogen levels steadily increase, causing your body to build up a uterine lining (called the endometrium) in which a fertilized egg can implant. In a normal ovulatory cycle, after an egg is released from the ovary, what’s left of the follicle that was housing the egg before it was released is called the corpus luteum. Then, for the rest of your cycle until you get your period, the corpus luteum produces progesterone, and estrogen levels drop. The reduced estrogen levels slow the development of the endometrium, but progesterone provides structural support to the endometrium until conception or the next cycle. If conception does not occur, the corpus luteum stops producing progesterone about 12-16 days after ovulation (this time period in between ovulation and the end of your cycle is also known as the luteal phase). This signals to the body that conception did not occur, and the endometrium is shed – meaning you get your period. This is also known as progesterone withdrawal bleeding. But if an egg isn’t released from the ovary, there is no corpus luteum, meaning your body doesn’t produce any extra progesterone. Without progesterone, estrogen is unable to support the growing endometrium on its own. So, eventually the uterine lining is shed, and you get what seems to be your period. But because ovulation did not occur, this type of anovulatory bleeding is not a true period, but rather is known as estrogen breakthrough bleeding.