So I've Been On The Implanon For About A Year

So I've been on the implanon for about a year and a half now. From the first month I have bled every 3 or 4 months for about a month at a time. I'm due for another one but it hasn't started yet. In the last month I have outgrown every single pair of jeans I own, eating way more than I ever have, boobs have increased in size, waking up in the morning with terrible headaches, getting headaches throughout the day, nausea throughout the day, and sore boobs. My doctor says it's not possible to get pregnant on the implanon but is he wrong?