Hi J.M, Welcome to HealthcareMagic Forum.
The ideal Blood Sugar level during Pregnancy
should be 70 to 130mg/dl before meals and less than 180mg/dl in less than 2 hours of your any meal. So in your case, it should be between 70 to 130mg/dl if you check it 2 hours after your Supper.If the sugars are fluctuating you should be seeing your Gynecologist. Go for regular brisk walks daily for 30 to 40 minutes, get adequate rest and go for regular follow up.
All the Very Best and Wish you Good Health.