Short answer: When あなた have one, you'll know.
Honestly, that was my first reaction to this. Sex feels good, but the female orgasm is supposed to be one of the best parts of it. When you're having sex, または you're alone with yourself, the orgasm is generally what you're building towards. あなた feel もっと見る and もっと見る stress as your body becomes もっと見る sensitive and あなた stimulate these sensual areas. During the orgasm, this building stress または tension is released. Eventually, your body will be so aroused from penetration, clitoral stimulation, and/or other sensations, that the muscles inside your vagina will repeatedly contract, sending out a pulse. The point of this is to propel semen through to the uterus. Other muscles in your body may also contract at this time. ハート, 心 rate and breathing quicken, and sensitivity is heightened. The orgasm is over when the contractions stop. Pulses occur about once a second.
Less scientifically, あなた might feel a burst of pleasurable sensation that might radiate outward from your vagina, and may leave あなた feeling a bit tingly.
If あなた feel this happening, you're having an orgasm. That's how あなた know.
For もっと見る information,
link.