Yeah, it is definitely ok, but keep in mind the timing for the MCAT. If you don't take pre-req classes your first year and none in any of the summers, then you will take gen chem 1 and 2 your sophomore year and organic 1 and 2 your junior year. So, if you wait to finish your classes before taking the MCAT, then you have a very small window of a couple months to take it and get your application off, so you can start med school without taking a year off. Now, you definitely can take the MCAT without all the classes, take it at the end of your junior year and hope you don't need to retake, or take a year off in between college and med school. All of that is perfectly fine, so weigh your options. I personally, would recommend you take at least Gen chem 1 your spring semester of freshman year, to keep your options open.