When should I take the OAT

Hi everyone, I am scheduling my oat exam however I have classes starting September 9th. I am taking immunology both lecture and lab, biochemistry both lecture and lab, and fundamentals of public speaking. I’m not sure if it would be a good idea as I think I would be really stressed with classes and studying for my oat. To schedule my oat I think it would be best if I take it early October. Any thoughts ?