Implant

I’ve been on nexplonan (arm implant) for almost a year, and my periods are so out of wack. They don’t follow any pattern at all. Usually the second day is the heaviest ever (tmi warning: but I can leak through an ULTRA tampon in less than 4 hours....) and then in between the month-ish time span before my next period, I usually have heavy spotting that needs a light tampon. I just don’t know what to do, I’m getting really annoyed by unexpected bleeding.... any advice? Or others who have had similar situations?