Art...that is a fairly normal amount of insulin for your stage of the pregnancy....your pregnancy related insulin resistance is at its peak between about 28 - 36 weeks so don't be stressing about it. As a very rough guide pre pregnant diabetics use up to 1unit pr kg of body weight. Pregnant diabetic women at your gestation use up to 3 or 4 times that amount. It is a very individual thing and has absolutely nothing to do with how "good" or "bad" you are...it is all do with how much of the insulin resistant hormone you are producing.......so if any doc says you are taking too much and is implying you are not looking after yourself, just nod you head and smile and internally tell them to rack off!!
JMHO for what it's worth.