Is doxylamine succinate safe to take while pregnant? I'm currently 12weeks. Have severe nausea and sleeplessness.

Ask your doctor. According to the FDA it is indicated for treatment of nausea/vomiting of pregnancy in women who do not respond to conservative management and it has a category class A for safety during pregnancy. You should keep in mind the warnings and reported adverse effects such as somnolence, headache, dizziness, dry mouth and hypersensitivity. Before taking any medicine, you should check with your ObGyn.