I have been having having stomach pains and back aches for longer then a month. I been on depo for 2 years. These symptoms started right after my shot on September 17th and haven't stopped. I tried a colon cleanse and a body detox. Both didn't help so what could be wrong?

Have you seen a doctor about this? It could be an unrelated illness. It could be the depo shot, but if you haven't had a reaction to it before, it is unlikely you're having one now.

Typically the "Detox" and the "Colon cleanse" will only cleanse your wallet of money. They're not really effective. Your bowels are constantly cleansing themselves, it's called dropping a deuce. Your kidneys detox your blood. It's what they do.

From rxlist.com:
" Depo-Provera CI should not be used as a long-term birth control method (longer than 2 years)... Tell your doctor all prescription and over-the-counter medications and supplements you use...
Side Effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

Menstrual periods that are heavier or longer than normal;
Sudden numbness or weakness, especially on one side of the body;
Sudden severe headache, confusion, problems with vision, speech, or balance;
Chest pain, sudden cough, wheezing, rapid breathing, coughing up blood;
Pain, swelling, warmth, or redness in one or both legs;
Fever;
Nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
Swelling in your hands, ankles, or feet; or
Symptoms of depression (sleep problems, weakness, mood changes)."