Help me out? Gas bubbles normal?

Hello ladies, so me and my husband have been trying for a while now, and I usually start my period every 4-4 1/2 weeks. Well I've reached the four weeks and still nothing. I haven't really thought about being pregnant until my stomach for this whole past week has been going crazy with air bubbles or gas bubbles, not quite sure what it's doing. It's never done this before, so it's definitely something new I'm not used to. Is this normal when first pregnant? Plus my chest is really sore as well. I just thought I'd see your guyses input on it! Tell me what you think or have experienced! 😘