hcg levels after miscarriage

Can anyone please shed a light on this! 
Found out I was pregnant 21/9/16, hcg levels 144 23/9/16 2 days later levels dropped to 114 which suspected miscarriage. I bled for 12 days starts off spotting for 7 then heavy bleeding for the rest no clots just thick red blood! Anyway yesterday 11/10/16 I did a test and got a positive test again! Since bleeding I've only had sex Friday just gone so 5 days ago. Hospital today said my levels are 112. Could this be a sign of a new pregnancy or could there be something left over from the miscarriage? I'm booked for a scan tomororw to see if anything is there! Thanks in advance xx