I don't think a few W's will make a difference.
IMHO I think grades are too over emphasized. Don't get me wrong...obviously they are important and GPA is a determining factor on which schools a person is competitive for. But W's or even poor grades aren't a deathblow. I have several W's on my transcript, including an EMT course in sophomore year (to my regret, I never completed the EMT course). In my senior year I received a C in o-chem II, a C- in microbiology, a C in neuroscience, a B- in Biochem, and did P/F in immunology. In other words, all the classes you don't want to do poorly in!!!
I did do an informal post-bacc at a different (albeit much lower ranked) school after graduation, which entailed re-taking o-chem II and 3 upper division bio classes. My first time around at school I was a dumb$*%. I did a lot better in my post-bacc. At the end of it all, my science GPA was a 3.60. Point is, I just got back from interviewing at Pitt, and have already been accepted at University of California, Davis.
