Am I pregnant?

I'm 16, and I have a boyfriend. We've been going out for a little over a year. We do have sex every now and then, but it's always protected. Anyway, about 2 weeks ago, he was just playing around, and he accidentally put the tip in, there was no cum thought. My period is 4 days late and I'm starting to worry, I have had headaches and I've been very tired! Help?