Nexplanon with positive pregnancy test?

For the past months I've been having feeling of nausea with vomiting. Feeling bloated. Decided to take pregnancy test I saw a very faint blue line on Saturday and another one on Sunday. Took a Clear Blue digital test this morning with first pee of the day and it came back positive. How can it be? I've had the nexplanon for two years and about 2 years and 3 months. Hx of PCOS. Please I can't fathom how this is even possible.

Update: Went to OBGYN and I came back negative on the pee test. HCG levels are less than 0.2. Progesterone levels are 0.29 with the lab values for ovulation phase being 0.06-4.14!