Welcome to healthcaremagic.
The implant and the pills you had might have given rise to hormonal
imbalance which has resulted in ph and the quality of the vaginal secretions.
This change in the ph and the secretion quality would have led to infections.
I strongly suspect that you have vaginitis
which is producing severe itch and the abnormal discharge.
Do visit your gynaecologist to be examined and confirm the same.
Wish you good health.