I Have Been On Nexplanon Since April And Have Taken

I have been on Nexplanon since April and have taken 9 home pregnancy tests and 6 of those had faint line positives. The other three were taken later in the day. Today I went to planned parenthood and waited 2 hours just to be seen and have them tell me I'm not pregnant and that there nothing they can say about my previous tests. I'm only 18 and about to graduate high school so I'm not ready for a child at all. But I want to know if I am pregnant for sure and what the faint line means if I am indeed pregnant I in no way want to harm my child by keeping this birth control in my arm.