Irregular cycles, inter-menstrual bleeding
and absent periods are all a side effect of the implant. Contraceptive
effect may dwindle as the effect wears off toward the third year and especially in the overweight
person, whose hormone requirements would be more. So, the spotting you have is more likely a sequence of the implant. You may see your doctor for further evaluation if you suspect pregnancy
(failure rate is only 0.05%). Take care.