Is a metallic taste in one's mouth an early sign of pregnancy?

A metallic taste in the mouth is called dysgeusia. It is an early sign of pregnancy. It can even occur before you have a positive pregnancy test. The cause of the taste is thought to be hormonal, particularly the increased estrogen associated with pregnancy. You can try mints and/or brushing your tongue when you brush your teeth. Fortunately, this problem usually improves greatly or ends entirely after the first trimester.