[Dark-and-Twisty]

It's normal for teenagers to have irregular periods (which is why so many teenagers stress over being pregnant, even when they've used protection). When I was younger, I always had the opposite problem - my period coming twice a month. Stress can definitely delay your period, so don't stress. If it'll ease your mind, take a pregnancy test; because as I'm sure you know, condoms aren't 100% effective even when used correctly. We can't tell you if you're pregnant or not, though the odds say you're probably not.