Can you get pregnant on implanon?

Hey ladies. I need some advice.
So I am on the implanon, but I have been feeling really weird lately. I have minor backache, headaches that is killing me, my abdomen has an uncomfortable feeling, I have been sleeping all day like a dead person, my gosh sleep is all I want. I cannot wear tight clothes because it hurts.
Is there a possibility of being pregnant or could this be the side effects of the birth control?