What Are The Side Effects Of Implanon Birth Control?

I am 21, 5'2, & about 115 lbs. I've had implanon for about a year. In september, I hada period after 2 months, & from then on, I've hada period every month for 2-4 weeks at a time! This time, I've been on my period for about 3 weeks. It looked like I was gonna stop, & then two days ago, I've been bleeding so much I've been changing pads every 30 mintues to an hour. It's like if I move around too much then it's worse. I've never had a period that bled this heavy in my life & I'm a little concerened because it's taken sooo much out of me.