I had this for my second pregnancy. Talk about annoying....It went away after the first trimester. My Dr told me too late, but he said suck on altoids, it helps with the taste and sometimes the taste goes away.
After doing a lot of digging, it seems that those few doctors who do recognize it believe the metallic taste could be a result of the body releasing toxins through the lymphatic system. Others believe it is the body's reaction to being run down with stress or the result of more physical demands being placed on a woman's body during pregnancy. Regardless of why it happens, rest assured, you are NOT imagining it.
Oh man, I totally had that. The day it started tasting really strong, I took a HPT and it was a BFT! It tasted like I had sucked on some silver jewelry. It only lasted a week and only comes back occasionally.