4w,3d post D&C and still no period...

Jess • I`m 28, Mama to Elyse Cecelia 8/8/16🎀 RIP angel baby 8/27/15😇
I had a D&C 4 weeks, days ago and still have not gotten my period. My blood hcg level was taken on 9/22 and it was 6. Shouldn't I have started by now?? We have had unprotected sex, and I guess if implantation didn't occur yet, it may have not shown up in my blood test yet. Hoping I either find out good news soon or start my period soon so we can start TTC again!!!