I noticed that you have a few of the BR oxford shirts from your outfit posts. I'm wearing it the blazer so it need to be fitted but I also don't want the fabric stretching where it buttons. Do you size up or down or are they TTS? I'm stuck between a XS/S, I measure apprx 34C, 27 waist. I've never had much luck w/size charts so I don't know if I should trust the one from BR.