There are certain indications that a woman has been satisfied. If she has a vaginal orgqasm, her vagina will contract several times and you should feel a slight squeezing sensation on your penis. If she has orgasmed through clitoral stimulation, her clitoris should be very tender to the touch. Just as some men cannot bear to have their penises touched immediately after an orgasm, women who experience clitoral orgasms cannot bear the sensation either.
Most importantly, you should do everything in your power to assure yourself that your partner is pleased. There should be signs such as flushed skin, heavy breathing, rapid heartbeats, erect nipples, swollen labia...