Can anyone help.

I am at my end on this. 3 months ago I went for my first contraceptive the jab. Everything seemed fine, I even stopped having my periods nice.
I had gotten thrush, got treatment for that. then straight after that I got BV Bacterial Vaginosis. Went to the doctor twice. they had not examined nor taken a swob of anything. The antibiotics i received for BV seemed to help, but now I have a strange Brown discharge, with a little bit of irritation but not much.
Can anybody help, because the doctors keep giving me medication which iether does not work or changes my symptoms.
Could it be because I am on the injection.