I was wondering because it seems as tho I can sing higher when I’m not trying to get my highest note out. Idk I thought this could be something that’s happening
It's not like there is a falsetto fairy shouting and raising a flag whenever you switch into falsetto. Of course you can be in falsetto without knowing it and vice versa. Knowledge comes with teaching and experience.
Both the Bee Gees & Green Gartside from Scritti Politti made their careers out of being able to sing falsetto at lower ranges than most people would naturally use.
They, of course, knew they were doing it.
Singing "quieter" is one way that towards the top end of your range to switch into falsetto, accidentally or on purpose. As you sing up louder, you should feel yourself switch back into full voice. Once you can feel the difference you ought to be able to teach yourself switch in & out of it at will - though not necessarily with the same range as these guys. If you work hard at it you can teach yourself to be able to 'slide' in & out of it rather than 'switch'; it's possible, but difficult, to be able to literally move from one into the other without a glitch, or even stay 'half way'.
There's another phenomenon that comes into play for most people. If you sing higher & higher until you "run out of full voice" you can get a bit more range by switching to falsetto.
I can't actually confirm how people do this, as I can't do it. I can either reach a note or not. I cannot 'go a bit higher' if I switch to falsetto. Never have been able to.
Bee Gees - How Deep is Your Love
Scritti Politti - Absolute
Anecdotally - I had to learn how to do this when I got the job doing most of the vocals on the original Pioneer video karaoke albums back in the 80s. You can go blue in the face trying to stay down low in falsetto; it's a nightmare of breath control until you get the hang of it ;)
It's possible, but not likely. If you don't feel any difference between high notes and the notes that you know for sure are chest voice, then either you have a very high voice without falsetto, or you're not aware that you're in falsetto. For most people, it's a pretty clear difference, but there are definitely some people to the contrary. It could also be head voice.