Alright, I'm going to be really descriptive and give every single detail to make sure I get as accurate of information as I can, so please bare with me.

My boyfriend and I became sexually active almost two months ago, and I'm not on birth control but we used a condom every time. One time, however, the condom got loose, but we quickly realized it and stopped. There seemed to be no pre-cum, and if there was any there's a good chance the condom still could have stopped it. 

A few days later, two weeks or so before my expected period, I started having this dark-red, brownish discharge that was very heavy, but not enough to be a period. It was a lot like what "implantation bleeding" is described as, but it lasted steadily 11 days.

It is now exactly a month since my boyfriend and I have had sex, and I am experiencing no symptoms but no period and my breasts are sore. I'll add that I am completely freaking out about this everyday, and my boyfriend and I are overly stressed and can't think about anything else but this possible pregnancy. Can someone help us out?

I'll also add that I'm 16, I've had my period for 5 years. It's been regular for 4 or 5 months, but before that it only came once every 3 months or so for the first 4 years.

Thank you so much for your help, everybody.