In the AAMC survey "on schedule to meet premedical coursework" was listed as "medium" importance. Given as much weight on the scale as your cumulative non science/non math GPA but less importance than overall GPA, MCAT, GPA trend etc. The importance each individual evaulator gives this is likely to vary to some extent.
https://aamc-orange.global.ssl.fast...5b5844a/mcatstudentselectionguide.pdf#page=12
If are talking about staying an excessive amount of time in UG(ie 7+ years in undergrad or something) that might perhaps raise an eyebrow or two and raise some questions. But many people stay an extra semester or two in college, dont sweat the small stuff. The reasons why you stayed longer in college also matter; someone who stays longer because they only take 9 credits a semester and are affraid of big workloads is different than someone takes 15+ credits a semester but who changed majors midway in college and decided on being pre-med late.
Keep in mind you can still take courses after you graduate and have them count towards your GPA as a post-bacc if it needs to come to that.