abnormal uterine bleeding
"I'm 16 and I have been on the depo shot 7 months so yes I've only had 3, 
I received my first in April, I was actually quite scared so my friend came with me but I didn't even know the nurse had finished then I received my second one two days late of when I was meant to, it was meant to be the Wednesday in July however I forgot about it and received it on the Friday 17th July for these I had no bleeding at all then in September I had this brown looking mark in My underwear and realised it's dry blood telling me I'm due my next injection soon. the nurse told me this could carry on a little throughout protection of this one and it is normal!  I had my 3rd one yesterday  9/10/15 and I was told this one may bleed but it will stop soon."