Letrozole question!

Hey laddies! I just have a few questions, I started taking Letrozole this cycle we have been trying for over a year with no success. I get a period every month and I do ovulate but my doctor still gave me the medication. I am on cycle day 17 and decided to take a pregnancy test because I have been spotting and it came back with a very faint line. I just feel like it’s way too early for it to be positive. This is my first round of Letrozole so I am not sure how it all works. Did anyone have a similar experience? Per the app I ovulate this week but my ovulation test have all been positive since I stopped my period.