You ejaculate in your girlfriend three time in one day how likely is she to get pregnant?

...Sounds like you're tempting fate. The highest probability of conceiving when a woman is most fertile (in the first week after menstruation) is 40%. However, doing it three times is likely to increase those odds. If she's on the pill or you used a condom there's no need to worry about pregnancy. If this is not the case... well, if it's been less than 48 hours buy an emergency contraceptive. If it's been longer, buy a pregnancy test.