The difference between a 4.000 and a 3.991 isn’t going to “drastically affect” anything. A quick search finds a published middle 50% unweighted GPA at UCLA of 3.38-3.90.
You will be admitted or not admitted based on a broad variety of facts and data. This one has zero impact.
A friend of mine freaked out over his 1st B in the first quarter of senior year. He graduated from Harvard, so it worked out OK.