Your urine being clear is GOOD SIGN. You want it to be clear, that means you are getting enough fluids in your body and it is ridding of all the toxins within. You cannot die from drinking the amount of water you are currently consuming.
The regulation of both the ovarian and uterine cycles is the function of several gonadotropic and ovarian hormones. Among the most important of the gonadotropins are luteinizing hormone (LH) and follicle stimulating hormone (FSH), while the most crucial ovarian hormones are the androgens, estrogen and progesterone.
The endometrium changes throughout the menstrual cycle in response to hormones. During the first part of the cycle, the hormone estrogen is made by the ovaries. Estrogen causes the lining to grow and thicken to prepare the uterus for pregnancy. In the middle of the cycle, an egg is released from one of the ovaries (ovulation). Following ovulation, levels of another hormone called progesterone begin to increase.