Not to be depressing but I had calculated my own science GPA and the one I got back from AADSAS was lower! I'm really not sure what goes on at AADSAS but they do seem a little screwy! I have never retaken a class and have no W or UW or audits, but somehow they calculated different than what I was expecting. Chin up though, your application includes much more than GPAs. You might have many more things going for you which none of us know about.