I didn't decide to take the Plan B pill, now i'm unsure?

Am I pregnant?

I'm 16 years old. I had protected sex with my boyfriend a week before i was supposed to get my period. When he pulled out, the condom was gone. We thought it came off. Later on, about 7 hours later, I found the condom in my vagina. I thought it just maybe got lost when he pulled out at the last minute. Everyone told me I should be fine, so I didn't decide to take the Plan B pill.I was supposed to get my period around today, but I didn't. I've been stressing out like crazy convincing myself I'm pregnant. I've looked up signs of pregnancy and I've been having headaches and discharge. I'm not sure if I'm pregnant or just stressed out and that's why my period hasn't come yet. PLEASE HELP! WHAT DO YOU THINK?