I've had the nexplonon inserted thursday last week,i got it inserted the same day i started my period how long should i wait to have unprotected sex??

Not this decade!: At 16yo, you should not be having unprotected sex. When you are married, you may have sex without condoms because of the risk of infection. That aside, Depo Provera, Nexplanon, and other hormonal birth control methods should be given at least a full month to control ovulation effectively enough to be relied on for birth control.