Can you get pregnant on implanon the 1st month?

i had my son still born at 5 months from placental abruption (placenta came unattached from the cervix) and i got implanon put in my arm at the beginning of last month and i have been sick almost everyday now . . my period still hasnt come its about 6 days late and i had taken a home pregnancy test about a week ago and it came out negative but somebody who has implanon told me that on the implanon hotline they called it said it can cause false negative tests . . but im already nervous because of what happened last time . . can anybody help me ?