Can I get pregnant while on nexplanon?

Hey ladies! I am currently on nexplanon BC since April 2014. My periods have always been on time and haven't missed one. Well my last period was Sept 28. I haven't had one since then but have had light spotting and feeling fatigue and experienced getting sick. Is it possible to get pregnant on nexplanon? I took 2 tests one was negative and one was indecisive. Please help!