Long Period, Had Unprotected Sex After First Depo-provera Injection, Back Pain, Cramps. Normal?

Hello, I am close to my third depo-provera injection . I am full aware of how effective it is and the consequences. However, I am still worried. My current period has lasted way over a week (nearer to two) and I m still bleeding . It s not specifically light or heavy, it varies. I have had unprotected sex about four/five times since my first injection on the 31st May, this year. I have what feels like period pains almost all of the time and I m starting to feel sharp pains in my back and also on and around my right boob. My stomach will often have more pains if I lean down onto it, more than usual. I am unsure as to whether this is normal for this specific contraception . Thank you for your help.