Yes its from hormones. There's a name for it I forgot what it is though. But try vinegary foods like pickles.
I did too... and still do now and again. Gum would make me sick and brushing my teeth wouldn't help. I found that eating small sandwich or a tost would help for 20-30 min but not for long :(
Yes earlier in my pregnancy i experienced a metallic like taste n mouth chewing gum didn't help for me it just go away on it own but it was nerve wrecking but its normal to go through that change should go away when u get further along