anyone experienced this rib/side pain?

You likely have gas. Are you constipated? Drink more water and eat only whole foods...colace if needed for constipation

This kinda sounds like what I've been having between 16-19 weeks which the doctors have just put down to things moving and stretching especially as I'm such a small build they said I'm more likely to notice changes but if it is concerning just goto the gp and get it checked out always better to have the all clear than to be at home stressing and listening to dr google haha

Sounds like round ligament pains from your uterus growing. I had that kind of pain in my right side but it wasn't anything serious. It's normal and you might even start to feel pain in your groin the further along you get. Also normal.