What should I do? SHould I dedicated 1 full day to chest or do bench presses on my off days? Thanks in advance!
You don't provide enough details about your current program/etc for that question to be answered.
I'd suggest a specialization program like "The Perfect 10" for chest (search archives for it). I added 2 inches to my shoulders by doing that program for shoulders and my buddy added over an inch to his arms with that program.