Anyone had this....

Hey girls am currently ttc for my 3rd baby. Have had 2 mc recently in nov and dec. My question is after the dec mc, i bled for 7days then it finished and things returned to normal, i.e hormone levels etc. Doc said to carry on as i was and to take day of mc as day 1 of cycle, well on day 15 i go this funny spotting, really dark traces of blood in my cm and sometimes brown, this went on for 5days had now cleared (on day 20 now) I have never experienced anything like it and was wondering if anyone has, am worrying it may of been a af, but surely to early and had normal cm too, just red mixed in sometimes. Have thought it could be something to do wiv mc but i went 8 days of no bleeding so surely that had all gone!!!!! Any help would be great, kim xxxxxxxxxxxxxx