Pantha - "statistically" most women manage to control their GD with diet/exercise only - so the fact you're getting great BSL's suggests to me that you're eating the right things just naturally even though you haven't changed your meals, and hopefully you'll be able to control it easily by eating well :D! Re a "normal" BSL, well I was told that my post-meal ones should be between 3.5 and 7.5. My endo also said that it's very unusual for PG women to have a hypo (i.e. go TOO low - under 3.5 I guess). My dad has Type II diabetes and he's had some hypos (which were those super low numbers)- so keeps some jelly beans & stuff with him just in case... but he's also on insulin & meds, and apparently that can make hypo's more likely. I'm not sure about the fasting BSL whether that has a lower limit, I'd ask them next time you see them. But certainly I think a very good BSL is in the 5's for post meal.
Re more sugar, well most DE's and dietitians i've seen are of the "sugar-is-evil" variety, so I doubt they'd say more sugar, but it might be about tweaking how much carbs/protein etc you're having. I guess that ultimately if you're not going hungry and your BSL's are great - well that's the best way to be!

