Implantation bleeding or period?

implantation bleeding or period ? The days I was ovulating was the 11th & 12th of this month. I did try both days. Now I’m having light blood on a tampon with brown discharge. My expected period is in 2-3 days . I’m having cramps yet they aren’t as bad as my period cramps normally are . They are more off and on then anything else . As well I took a pregnancy test and it was negative.