Sounds like you are doing awesome! I don't think you have to pump the other breast, but it can't hurt. Just make sure you are switching back and forth. Like you said, don't over do the pumping or you'll start overproducing.
Great job! If you are worried about those last 2 oz, you can wake at night, after about 4 hours, but w/ only 2 oz left to gain, I don't think you need to stress.