Hello,
If you stop getting Depo-Provera injections, your period usually returns within 3 to 10 months but sometimes it may take 12-18 mths. In your case, this soreness can be due to hormonal changes due to depo shots.
However other important causes are fibrocystic breast disease,ductal ectasia, mastitis(inflammation of breasts),galactoceles,benign and malignant pathologies of breasts, referred pain from liver or musculoskeletal system,arthritis of the ribs, costsochondritis and inflammation or sprain of pectoralis muscle.
I feel that an examination by a gynecologist will be the best if the symptoms persist for long. Till that time, apply some warm compresses on the breasts and take some over the counter pain reliever(analgesic) like ibuprofen or diclofenac.
I hope it helps. Take care and regards.
yes could be. or there could e an infection in ur breasts you should see your doctor to be sure your hormones are obviously up the left too. poor girl