There are all sorts of weird pregnancy symptoms. Keeping yourself hydrated is really important.
Later in pregnancy, I became really thirsty and craved ice water . I read an article later that stated that this could be a symptom of iron deficiency, which I later found out I had slightly. No big deal, they had me take an iron supplement and I was fine... but just an idea.
Really, just drink lots of water
Congrats to you!