Positive line on pregnancy test/ nexplanon

I have been on the nexplanon for 9 months now

The past 2 months I have had spotting and bleeding, on and off, very bad cramping, tiredness and feeling sick.I decided to take a pregnancy test and it has came up with a faint line, I took around 4-5 test and they all came up with the same result within seconds.

This is the first time on the bar! Has this happen to anyone else? What was the outcome?

I have a doctors appointment in 3 days but feeling worried! They lines look a bit darker in person