how are you all doing? my girl friend and i were wondering something. We had unprotected sex for 5 sec. until i put a condom on about 2 weeks ago. Now her period used to come around the 18th but it has gotten a few days early in the past few months (as in 15th, 16th, 17th). Then last month it came 2 weeks early from her being stressed out and everything. Now the end of last week it was supposed to come but didnt yet. Is it possible for it to come later back around the 15th?
Many things can effect a woman's cycle- stress and another being pregnancy.
Though have you had unprotected sex since that time? I see that you didn't seem to have ejaculated at that point before putting the condom on- though this does not mean that semen could've come out anyway.
Since this is sort of a late response to an older post, my first suggestion would've been to get emergency contraceptive if you were worried about her being pregnant. If I remember right, it's good up to three days (72 hours), though most effective the day after (hence, "the morning after pill" which is Plan B).
However, since this is an older post, and she doesn't seem to have missed her period yet, then I wouldn't be too worried. Though to set her mind at ease, she could take a pregnancy test. Also, if she has missed her period, then she should get a pregnancy test in that situation as well.