Implantation bleeding or AF?

Hello ladies!

So my period came in a week early.. Since Saturday night I started having light cramping and just yesterday I began having brownish-reddish period, but it's so light. My estimated ovulation day was July 3rd.

Do you think I'm just having an early, odd period or could it be implantation bleeding? Can I take a pregnancy test now or should a wait a few days?

Thanks!