Recently stopped breastfeeding, I have the arm implant for birth control and woke up this morning & threw up + sensitive to smell?

Pregnancy test. Do a pregnancy test. Implanon is one of the most effective birth-control methods there is but its still not 100%. Best wishes!
Get yourself checked. Symptoms like throwing up etc soon after an implant device deserve a closer look for the possibility of an infection in which case the device may need to be removed.