Nexplanon pregnancy??

I've have the birth control implant in my arm since February of this year, I've had the normal random spotting at first then it went away after the first couple months, I started light spotting again in July which lasted about 3 weeks non stop. & I also don't get a period anymore, but for the past week or so more I've been extremely nauseous most of the time out of no where and i find myself just feeling sooo tired throughout the day, by the time I get home from work and school I wanna crash. Oddly how I felt before I found out I was pregnant with my son.. I've been trying to figure out why I've been feeling like this and being pregnant was the last thing I thought of.. If I took an at home pregnancy test would it even tell me if im pregnant? Since I'm on birth control..