Your thoughts: pregnant or not?

So 10 days ago me and my boyfriend were having sex and the condom broke. We didn't realize it until after everything was said and done. I'm not on any form of BC so I took Plan B 12 hrs later. I looked at my calendar and it was approx 4 days after I last ovulated. Yesterday I was supposed to start my period and I had some very light spotting (brownish pink)...much lighter than usual. I thought it was my period but since that small amount I've had NOTHING. A tiny amt on my tampon but that's it. Zilch otherwise. Do you think its my period showing up and the Plan B is messing with it or do you think its a possibility I could be pregnant? I was hoping I was in the clear. My boyfriend and I are plenty old enough to face this if I am in fact pregnant, just not exactly personally ready to do so yet. So please no judgy comments. I only need thoughts and advice from people who actually want to help. Thank you to those who do!! :)