As you probably know, there are lots of ACL threads with lots of info. In my case, my injury did not bother me after a few days. But if I loaded it in just the wrong direction it would go out. My ortho surgeon said it was what prior generations would call a "trick knee". Going out felt wrong but did not actually hurt after the first time.
Unfortunately there was some cumulative loosening and eventually I tore the meniscus. That hurt a lot and lead to surgical repair.
Many people, including some high level skiers, get by without an ACL. I think the key is targeted strengthening of the stabilizing muscles, which I did not do.@marznc
is our guru of ACL literature.
But the first step should be a real diagnosis.
It is also possible to sprain ligaments without fully tearing. My non-expert understanding is that some of the other knee ligaments (which could be your injury) have more blood supply and are therefore more able to heal.