Bleeding after post abortion bleeding

Patient: Hi,I had abortion on 15 July 2015, had heavy bleeding for 12 days. after that my doc done sonography , result was ok.gave me contraceptive pills , I took it for a week[Its actually 21 days course. But I have 1 yr old baby, i breastfeed her, so I fear to get side effects of pills to her so stopped after one week dose. ]. I dont have bleeding for 2 weeks, now from monday I am not taking pillls and from last night having light bleeding…plz tell me why it is? is it serious issue?EDIT:Thank you, it helps me.

Symptoms: Bleeding after post abortion bleeding