Had A D&c Following A Miscarriage 7 Weeks Ago Today.

had a d&c following a miscarriage 7 weeks ago today. I had my negative pregnancy test 1 weeks after d&c and only bled for 3 days. I had negative tests up until this Monday just gone. I had 2 positive tests, one wss the clear blue digital and said 1-2 weeks pregnant. I had a blood test Wednesday and I have hcg in my results. I have done tests since and all show negative. I have started lightly bleeding tonight and due another blood test Tuesday. Please can you advise what is happening