check out this page. It has some info on the metal taste in reference to pregnancy.
http://www.whattoexpect.com/pregnancy/symptoms-and-solutions/metallic-taste.aspx
This page has a more general overview, including pregnancy, but not at all limited to it.
http://www.healthblurbs.com/many-causes-of-metallic-taste-metal-taste-in-mouth-and-taste-of-metal-in-your-mouth-symptoms/
Good luck!
There is always a chance, i'd take a pregnancy test and see! good luck!