Is there a chance that I am pregnant from doing this?

I am fourteen, and I am worried that I may be pregnant. About a month ago I was at a dance and I was grinding with this guy, I know, stupid. I think that I felt him get a ***** and I think I felt a little wet on my dress after. Now I only got my first period in April, so I am a little irregular. But, I am now over a week late with my period! aah! I have never had by the way. Should I get a pregnancy test done or take one at home? I really would like to avoid that embarment, and that is why I posted this question! Please answer!