Science pre-requisites during undergrad or post-bacc

I’m three years into a degree in communications and have the chance to extend my time as an undergraduate to complete my science prerequisites before graduating. I’m wondering if I should delay graduation and work through all the course work or should I graduate on schedule and do a post-bacc.

Obviously sticking around and completing the science coursework in my undergrad would be less expensive but I want to get the best education possible and demonstrate my ability to work through upper-level courses. Would most medical schools look more favorably upon science coursework completed in a post-baccalaureate program versus during my time as an undergraduate?