Hi i'm about 34 weeks pregnant and have gestational diabetes i suddenly want to smell rubbing alcohol is this normal?

Not terribly unusual: It't not terribly unusual for any pregnant woman, gestational diabetes or not, to suddenly have urges to want to smell or taste things that are not necessarily normal things most people want to taste or smell. As long as it's safe for the baby, it's fine :-) As long as you are not smelling it for long periods (a sniff here and there), it should not harm the baby