Me and my girlfriend almost had a full sexual intercorse. I didn't fully penetrate her but I was pre-ejaculating a little. Later that night she said her mouth was watery and that she started to cramp. That went on for about a week and then her period came on normally. Is she pregnant?

You do know how pregnancy occurs, right?

No one can tell you for sure, but... if she got her period, chances are she's not pregnant.

So my question is this. Why are you having sex if you're not ready to be a daddy?

Here's some facts for you. Even if you use birth control, even if you use every form of birth control at the same time, if you have sex, pregnancy is possible. No form of birth control is 100% effective. No birth control is like putting a loaded gun to your head and hoping the trigger jams.

So, if you're not ready for a baby, either lower the risks by using birth control (lower, not eliminate) or stop having sex.

Chances are not this time because she had a period, but there could be some chance ( small)

How old are you? This sounds like something your way too young to be doing.