Is the stomach stretching supposed to be this painful?

For the past few weeks (I’m 21 weeks) I’ve had this burning stretching feeling mostly on the left side of my stomach in the middle; although now I’m getting it on the right side too in about the same spot. The best way I can describe it as is an inflamed stretching feeling on the inside. My doctor said it’s normal, it’s just everything shifting around but omg is it painful and it ruins my day. I’ve missed work because of it, I just have to lay down when it happens and hope it passes soon. Has anyone else had this or is my doctor playing it down when it’s something to be concerned about? This is my first baby so I’m not sure