beatrix,
i had the implanon in for 3 months, i had exactly the same problem except my bleeding would last for a few days at a time... i spoke to my gp and even went to another one to get a second opinion, they both said thats normal with the implanon, some people have no bleeding while others get the spot bleeding either sporadically or after sex... its completely normal... doc said it should go away after the first few months of it being put in... hopefully it will start regulating itself soon

cheers