Thanks for the query.
Since you have both diabetes
and hypothroidism, its considered high risk condition.
You need to keep your sugars in normal range to prevent birth defects to fetus.
Avoid excess weight gain during pregnancy
. At the same time do not diet as well.
Avoid sweets and high carbohydrate
Get a GCT at 20 weeks followed by GTT.
Continue taking eltroxin
Hope this helps.