Just to clarify my earlier point, achieving level 4 in a foreign language will satisfy the 4 year requirement for 99.99% of US colleges. Someone may come up with a case where this does not apply, but the only exception that I have ever found to the level achieved versus years in HS is University of Delaware (which no longer lists it on the website, and only required 2 years anyway) and some small college in the midwest. When I was going through the process a few years ago, I specifically asked this question of all the colleges I was considering (admittedly, still a small subset) and they all said it’s the level completed that matters. So really, the only question is science.
For those schools, you are fine as is. If one of your targets specifically says 4, then you should reevaluate. If they simply say 2-4 or 3-4, you’re covered and the additional year will not improve your application much, if at all.