advice please, am I pregnant

First time poster.. 
I'm on nexplanon (replaced in november). I'm two weeks late. I took a test over a week ago as I just felt weird and it came out negative.
Today, I felt like I was going to pass out in the grocery store after seeing some raw meat which normally wouldn't bother me. I came over all dizzy and knew if I didn't get out to the fresh air I would puke everywhere.
I came home and took another test which showed a faint positive. 6/7 mins later (outside the 5 min window of accuracy) the faint positive line had disappeared entirely. 
What do I do?

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