Me and my boyfriend had sex I had my period 2 weeks ago when should I start it again so I will not know that I am not pregeant.

Well if you just had sex and your 2 weeks from your period you are probably at ovulation so you are fertile. You will have to wait for your next period and if it is late by two weeks go get a test done. You period should be in about a week and 1/2 away.

Just a suggestion that is helpful to some women : start putting your cycles on a calendar so you know when you are supposed to start next. That way you don't think you missed a period and start worrying, when you really didn't miss a period.

Also, you didn't mention if you were using birth control. If you aren't, I would suggest that you do so. Although it isn't 100% effective, it will greatly decrease your chances of getting pregnant. :)