I take an injection and a brown eraser ...

I had a daughter in December 2010 and on 04/02/11 I took the 1st quarterly contraceptive injection, the 2nd injection was applied on 04/05/11. As I did not find + the CONTRACEP in the market my doctor prescribed me the monthly injection CYCLOFEMINA. I applied to CYCLOFEMINA on 04/08/11, the day that the quarterly injection would be applied. On 04/09/11 I applied the monthly injection again. 09/30/11 began to emerge a brown eraser, would like to know what this is, if there is any problem? That is the beginning of menstruation, because I left very little and I am afraid. Thank you very much in advance.
Expert answer:

In fact this should be bleeding compatible with a "menstruation", because with these contraceptives you will not have a "normal" menstruation.