Spotting instead of period

So my period was support to start yesterday, and I put in a tampon to check, and there was red blood. Not a lot, and it never came out of me. Today there was pink brown spotting on my panty liner, and the blood in my cervix was bright bright red and sticky. I took a pregnancy test the today and it was negative. Is this implantation blood? I’m on the pill and we use condoms.