HELP AM I PREGNANT?!?

Ok so me and my boyfriend (16 an 17 years old) had sex about two months ago the day after my period ended and the condom broke before he finished (he did not ejaculate so all that was in there was pre cum). We were very careful (we always are) and we always use a condom. I'm not on birth control because I don't feel comfortable messing up my hormones and stuff. I'm really sensitive to medication and I'm also a teenager with strict parents. However we are careful. Every five minutes he pulls out to check and he pulls out when he finishes too (again with the condom on) so after about three to four hours of panic we decided to get plan b. I took it with water but on an empty stomach. I got side effects with bad cramps and fatigue. I thought that would be it but the time for my period came and it wasn't there. I thought this would be normal so I just waited. About a week later I had some dark brown discharge (the kind I get right before my period starts) but no blood. It's two months later now and I just got a spot of blood today and I'm having bad cramps however when I wipe, it's more watery/clear. I'm hoping this is my period but if I was pregnant, would I be spotting two months in? I'm very scared. I'm just a kid. As much as I would love to be a mother one day, I'm not ready rn. It's hard finding time to get a pregnancy test without getting caught or noticed in a store. My boyfriend is very understanding and helpful and supportive. We've been together over a year and just recently started having sex. I don't know what to do please help. 
UPDATE: I'm four days into my heaviest period ever. I'm definitely not pregnant. Thanks to all of you who commented. Me and my bf are def. more careful and taking things more seriously now.