I have movement, firmness and pressure in my belly - any idea of what it may be?

Hmm seems like you have a lot going on physically. I've never had gallstones or any of that but I have a toddler. If you've never had a baby before you usually don't notice movement until 4 or 5 months into it but everyone's different. My advice, take a pregnancy test and see if you are prego. The most accurate I've found is the digital telling you if you're "pregnant" or "not pregnant". If you're not pregnant then you do have to go to the doc and have this checked out, it could be serious since you already have so much going on. Good luck.