Regular BBT chart, regular positive OPKs that correspond with it...... why am I not pregnant?!

I know sometimes it just takes longer for some people, but for those of you who had/have this “issue” (everything looks right on your bbt chart and with your OPKs, and you’re having sex on the right days) but you still aren’t getting pregnant, what ended up being the cause of why you aren’t getting pregnant? If you know/if there was one? And what helped you get pregnant eventually if you did?

I’m feeling super hopeless because looking at my temps and my OPKs everything looks “right” so idk what I can do ☹️