Im 32 weeks pregnant and in the past 4 week i have lost 3lbs and havnt gained any at all.?

As of right now i've gained a total of 19 lbs altogether, i have two other children that i gained close to 40 lbs with during the whole pregnancy, what could be going on...Dr mention to be eating 3 times a day and 300 more calories than when im not pregnant but i haven't had much of an appetite and she said the baby could be hypoglycemic...im not sure what that is...any advice would be great!!!