I wouldn't worry too much. There's a very good chance that it just tasted weird because of hormonal changes you're going through. It's quite common to become more sensitive to certain tastes, like one of the minerals in the water for example. I can't drink tap water when pregnant, tastes absolutely horrible to me.
But even if there was an actual weird taste, the most likely explanation is that the water had been in its bottle for too long and some of the chemicals from the plastic have seeped into it. That wouldn't be great but I'm sure that one sip (or even a few) would be way off the levels you'd need to be concerned about. Plus your body's really good at filtering out the bad stuff and not letting it get to baby.
Basically, try not to worry! Chances are it just tasted weird to you anyway.