Trying to conceive and i think i may have felt implantation last night. without thinking i rubbed three drops of lemongrass essential oil on my skin ?

Politely: you did not feel implantation, it is not possible to feel implantation. Implantation happens (when and if it happens) 6-7 days after ovulation, maybe as late as a few days afterwards and is too subtle to feel in any way. A pregnancy test is reliable 1-2 days before the expected period, or 11-12 days after fertilization. What are you worried about? Good wishes.