Am i okay to use nicotine while on nexplanon? if not what would the safest birth control be that i can use it on?

The problem combining smoking with hormonal birth control is the increased risk of blood clotting, which can have serious, even fatal, consequences in young women. Studies show that there isn't a significant difference in the types of birth control that increase this risk. There's little research yet on smokeless nicotine use and clotting risk, but until there is, you best not tempt fate.