Stitch like pain under ribs at 16 weeks pregnant

Starting tonight at work ( I do work on my feet a lot) I started to get a stitch like pain that starts underneath my left rib and kind of to the side and it feel’s a little better now when I lay down but I can feel it when I breathe in. It did start when I was eating my lunch and disappeared then before I got off work I started to feel it again. Do anyone have an idea what it is? It’s really uncomfortable