NEGATIVE TEST BUT STILL HAVE NOT MISSED MY PERIOD

Hey everyone! I have been using this app for about 1 month now and I know it's a prediction for when I am ovulating but I've been avid on hitting as much of my fertile window as possible and I'm getting my period in 3 days or so and I took a EPT test but it came out negative 😿 Is there perhaps a chance it's wrong or not accurate I've been ttc for about 4 months now I believe maybe over even and I'm just starting to worry I'm infertile