Nexplanon and Pregnancy.

Ok so I have the nexplanon, I got my second one in August after having the other for 3 years. 
I normally don't have unprotected sex, last month a condom tore during sex and I took a test at the end of the month and it was negative just to be safe.
For the last 2 weeks I have had an aversion to food, just the smell of food makes me want to vomit and I had straight clear liquid diarrhea earlier. 
Has anyone gotten pregnant on this birth control? Could I be pregnant even though the test was negative?