eft cheating question

if i injected a cheat while on a account and didnt inject it again, when that cheat eventually gets detected, will that account be banned?

That really does depend on a lot of factors, such as if the cheat was detected at the time when you injected. BE is known to delay bans, but usually for no more than like a month, often less.
I never recommend cheating on a main account, regardless of what you use. If you are not willing to risk losing an account, don't cheat on it.

I injected it around 2 and a half months ago, do you think I’m good?

yeah you're totally fine

I think I know what your asking and the answer to that would be no theoretically. Depends on if they do a delayed ban or not as well. If you inject while the cheat is detected it may not ban you automatically and could be a delayed ban which means you could be banned days or weeks later. If you inject one time when the cheat is undetected and later it gets detected you will not be banned. Just make sure to clear the loader or any files off your computer if you want to stop cheating.