Seriously TMI!! Any input please!!

So when I was 10 dpo I had a tiny tiny spot of blood (thinking maybe implantation) last night I had horrible cramps and my boobs hurt. Glow says I'm not supposed to start my period until the 29th. So I took a test today, bfn. A few hours later I was bleeding so figured my periy had started. Had a tampon in for maybe 4 1/2 hours and took it out. There was only a small amount of red blood on it and alot of think brown slimy stuff... Any ideas??? Any input would be appreciated