How long?

How long did it take you to get pregnant while not actively ttc. We’ve been doing this for close to 15 months now and I saw somewhere (cause everything on the internet is true 😜) that if you’re not using protection even if you aren’t trying to get pregnant you’re considered ttc and after a year if you aren’t you should see a doctor as there might be something wrong? I had my first two daughters while on birth control so this time you would think it would have happened since we don’t use anything