"Implanon (etonogestrel) is used as contraception to prevent pregnancy. It is in the contraceptive drug class. Common side effects include nausea, stomach cramping/bloating, dizziness, headache, breast tenderness, acne, hair loss, weight gain, and vaginal irritation/discharge. Pain, bruising, numbness, infection, and scarring may occur at the site where the rod is placed"
Honestly, sounds just like normal symptoms to me.