My only problem with implanon is irregular bleeding. I've had my implanon in for almost 2 years now and have gone from anywhere between 10 days to 60 days between bleeds - no pattern to it. Bleeding for me lasts between 4 days to 16 days - again, no pattern. I'm keeping a log of when I bleed and for how long now and with one year left of the implant I'm noticing some changes, ie: bleeding seems to happen every 24-30 days now, but I also have thyroid issues now which are effecting my periods too.