I am 24 years old and was taking the depo shot. However I stopped it this past August. My husband and I are trying to conceive; however no such luck. I just started having what I would consider my period in Dec. and then again in January both which were very light. On Feb. 3rd started off red then brown and lasted until the 8th. Now on Feb. 17th started again pink then brown and still going. Could this be implantation bleeding or just hormonal imbalance? Any suggestions?