Hi Doctor I am a 24 year old married woman. I don t have any kids yet. I went on the 3 months injection Petogen Contraceptive in May 2012. I didn t go back in August for an another injection. I didn t get my periods in August but at the end of August my breast started to swell i got my periods on the 20 of September and ended the 26th then 6 days after that i got my periods again from the 2nd of October to 8th of October. My breast is still swollen, sore, heavy, paining and i felt in both breasts a lump. Can it be of the depo injection? Please advice, i am quite worried.