On bc (implanon) light period slimy discharge with it excessive cramps for 3 days few blood clots what does this mean ??

Hormonal changes: It's not unusual to have abnormal bleeding on the progesterone implant Implanon. The chance of being pregnant on implanon is virtually zero. It is equal to or even more efficacious than sterilization procedures. So a tubal(ectopic) pregnancy is not a consideration. Check with your Gyn if an abnormal pattern persists as occasionally there can be other causes of unscheduled bleeding.

Suspect STD, PID?: Any abnormal, new, unexplained vaginal discharge, bleeding, or low abdominal pain needs professional evaluation. You have all three. At your age, these symptoms are suspicious for infection, especially an STD, perhaps with pelvic inflammatory disease (PID, fallopian tube infection). PID is the main complication of chlamydia or gonorrhea, so get care ASAP, for sure before the weekend. Good luck!