Sure, the bleeding is more likely to be from some other cause than pregnancy, since the often-heard-about but almost never seen 'implantation bleeding' is more mythical than real. But you asked if there is anything to be worried about, and simply by the timing alone (two weeks from the next period is a great time to ovulate) there would be the chance of pregnancy.
It is suggested to see a gynecologist once you become sexually active but I would definitely start seeing one. I agree with AnnieBrooke as well that if the sex was unprotected, you should be worried about pregnancy. But if that was the first time you had sex, your hymen probably broke, causing bleeding.
Well, if the yanno was unprotected and you expect you are two weeks or so from your period, I guess you should be worried about being pregnant.
By all means, see a gynecologist, to get a pap smear and the usual exam, and also to test for pregnancy if you do it in more than two weeks. You can ask all the questions you have for him or her.