Pregnant?

I am now 8 days late on my period and me and my boyfriend didn't use a condom for a few minutes before putting one on a couple weeks ago. I'm getting really nervous. I'm only 17 and definitely don't want a baby. How long do I have to wait before I can take a test? Help! 
Update:
After being 11 days late I started bleedingg but I'm still kind of nervous about this. I was going to take a test on Friday to see and idk what to do now.