Where's my fertile window?..

Back then Glow would show my fertile window, but now it doesn't pop up. I did input that I started the implant as my form of birth control about two months ago. ( I got it in May, but didnt place it on the glow app until around July ) is that the reason why I don't get fertile window alerts ? In general I know the fertile window begins shortly after my menstrual cycle and lasts about a week.