[QUOTE=Quote (foru_jack @ Nov. 17 2004,06:15)]she is supposed to get her periods by 14 th & it usually comes at right time but she didnt get it till 17th & i m afraid she will bcom pregnant.[/QUOTE]
Yeah you'll have to give us longer than 15 minutes between posts to respond, lol.
Ok from this quote it sounds like your g/f actually got her period but it was only 3 days late? did I read that right?
I just noticed it... b/c before I thought she is still waiting for her period? I dunno?
Oberon was right about stress. Besides, young women's cycles can be crazy even if they've always been normal. Especially if you start to become sexually active b/c you are constantly worrying if you are prego, etc.
Mine was always pretty constant. It came within a day or so of when I had predicted. One time, I was a week late, I was freaking out. So I took a test, and it said negative. Still, I continued to wait another week and took another test, still negative. Then my period finally came 2 weeks late.
I don't remember being under any different stress before that, but I know I was definetly stressed to the max those 2 weeks.
If your g/f has already had her period, or is on it now, then she is safe. There are those rare rare cases when women will have a period when they are pregnant. But for the most part, that indicates you are OK.
Yeah and there's no way to stop pregnancy other than abortion. As Oberon said, the morning after pill has a 72 hour window period. After that, its not effective.

Hi Foru Jack and welcome!

First, a word of posting advice.  You don't need to post the same question twice.  If someone has an answer, they will post the topic.  If you post the same question over and over, people can get snippy...

Okay, to your question... Unfortunately, condoms are NOT 100% effective.  It's really only 97% or so.  That means out of every 100 condoms used, there are still 3 pregnancies.  To decrease those odds, add a spermicidal gel or foam to your things you NEED for sex.  And don't rely on the condoms that already have a spermicide applied.  

Now, as to your girlfriend's period... many things can cause a woman to have an irregular cycle or miss a period altogether.   One of the main ones is stress.  So between it being your first time and then worry about pregnancy, I'm sure she's a little stressed.  There is a pill that can stop pregnancy (the "Morning After" pill) but there is only a 72 hour (I think) window to use it.   If it's been more than 72 hours since you had sex, then you might want to get a pregnancy test... if nothing else, to relieve your worry.  

Just remember for the future, the more forms of birth control you use the better.  Personally, I'd recommend birth control pills for her, condoms for you, and a spermicide during sex.

Good luck and take care.