Help!?

Ok ladies, just looking for some insight...

I had a mc that started on Dec 1, stopped bleeding on Dec 7. I passed everything naturally, and my hcg level was at 1.68 2 weeks ago, so since its below 6, they won't check again. I have been doing opks since the day after I stopped bleeding and have not gotten a positive. My cervix feels open and kinda low, as far as hard/soft, its medium. I also have been spotting after sex for the past week or so.

Any ideas?