Thanks for the query.
Implant can cause side effects like cramps, head ache, amenorrhea
and irregular spotting etc.
So more possibly the pink discharge you noticed could be side effect of the implant.
And it will usually subside soon.
You can go for pregnancy
test once which will clarify the doubt regarding pregnancy.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429