I got the nexplanon implant around 2 months ago, and I had my normal period and then the "period" from the birth control, so everything was normal and went kind of like my doctor said it would. It prevents pregnancy after 2 weeks and I've had it longer than that, but I heard nexplanon doesnt work if you smoke marijuana. I looked it up and there was nothing on it, but I'm just scared because I had sex around 3 weeks ago and I didn't get my period when I was supposed to, although the implant can get rid of your period. It's just a really confusing situation, I don't know what to do!