thanks for sharing your concern.
IMPLANON is used as birth control measures. if you feel it could be due to this then you must visit your gynecologisit in this regard for detail information.
remember it could be some allergic reaction
too,which will regress after discontinuation of that particular agent.
it could be stress induced or some vitamin deficiency
get yourself clinically evaluated thoroughly meanwhile take multivitamin
observe the changes in the lesion,and report to your dentist
during this period maintain good oral hygeine.
use antiseptic mouthwashes too.
for local application can use dentogel.
hope this helps.