Can too much vitamin A be a bad thing?

Yes. You need some, but too much can be toxic. The Institute of Medicine recommends that you get 770 µg of vitamin A per day while pregnant. More than 3000 µg per day while pregnant can increase the risk of birth defects. But rest assured that your balanced diet and daily multivitamin is not likely to give you more vitamin A than you need. Ask your doctor if you're concerned.