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.
During the second half of your cycle, progesterone increases and causes the lining of the uterus (a.k.a. the endometrium) to change so it can nurture a fertilized egg. If you do not become pregnant, production of estrogen and progesterone drops, and part of the endometrium is shed as your period. When to call your doctor: 2  If you're not pregnant and your formerly regular periods suddenly stop for three months; or if your cycle changes drastically (with your periods becoming infrequent -- more than 35 days apart, for example).