Advice please!

I found out I was pregnant on October 28th, had a natural miscarriage on November 5th at about 5 1/2 weeks along and Dr said everything cleared out, bled for about another 5-6 days, and starting two days ago (the 28th) I started very very lightly spotting. Literally one drop of brown blood two days ago, a tiny bit more brown yesterday and today same thing except very dark. Also I have had very mild cramping off and on for a few days. Is this the start of my period or could it be implantation of possible new pregnancy? Any insight is helpful, thanks!