confused AGAIN !!

hi just wondering if any1 can help ? had my baby last april at 6 wk check i had depo injection for 6 months ran out 2nd week in november and didnt go bk 4 it coz for the 6 months i was on it i bled twice for 2 weeks which was heavy and ive never had heavy periods so didnt go bk for the 3rd injection but then in january ive started havin a bleed just the once durin the day but it as been brown n happend few times now with it been every few weeks.... im confused and dont know why its happeneing as ive not been on the injection since nov so thought it would ov ran out by now ?? this past week ive also had clear discharge and white discharge too also had intercourse too ? as this happened 2 any1 else before and wot was the outcome ?? fingers crossed sum1 can help ?? :?