Stage Three - Orgasm

This stage is also called climax. During this stage:

muscles in the outer third of the vagina contract in a rapid series of pulses
the first contractions are the most intense and the closest together
the muscles in the uterus also contract
heart rate, blood pressure and breathing are at their highest rate
the skin may appear red or flushed (this m
ay begin in earlier stages)
Orgasm is the shortest of the four stages, usually measured in seconds.

Just before or during orgasm, some women release a clear fluid from their urethra. This is now commonly called female ejaculation. Most researchers believe that this is not urine, but instead a clear fluid similar to the fluid containing a man's sperm. Ejaculation is most likely to occur when a woman is being penetrated vaginally and pressure is being applied to the top wall of the vagina. This is where the back of the clitoris meets the wall of the vagina and is sometimes called the G-spot.