I Am On Depo Provera, And Should Be Getting Me

I am on depo provera, and should be getting me shot in 2 weeks time, i also have had introduced a new sex partner in my life, and we haven't been using a condom; no accidents since we've started dating. The reason i am here is that i am rather confused about this type of discharge i've been having. its brown closer to the colour of a close to finished menstruation and isn't really looking like a period. I have very mild cramps on the left side closer to my pelvic bone. I do not feel nauseous, tired, or bloated. i have a sore throat and I do have dry skin on my face though which is rather new too. Could you explain what all this could possibly mean?