I Believe I Am Pregnant. I Pissed A Period So

I believe I am pregnant. I pissed a period so I took 3 Pregnancy tests and all came back positive. However, I'm having a little tiny bit of brown discharge when I wipe here and there. Only been going on for 2 or 3 days now but is this okay? Could I still be pregnant? Also can you miscarry before you know you're pregnant and still have a positive result on a test? This is my first so I'm very nervous, scared, and excited.