What?
3.9 is not really a “holy mark”. It is all based on context and how your peers are doing. If dropping .02 GPA dropped you from top 10% to top 25% or something ridiculous, THEN you should start worrying. Otherwise you’ll be fine. No college will reject you with a 3.88 GPA, unless your school is so competitive that a 3.88 is only in the top quartile or something… Once you show academic proficiency, (which is obvious through your GPA, SAT and hopefully rigorous schedule), then they move on to your essays, EC’s, recs…