Is this pain normal?

I am having a dull strong aching pain whenever I am breathing too deep or when I stand up to walk or walking. When I pee it is pressure on the right side between my back and lower rib. Just sitting down I do not notice it much until I move. I cannot sit up straight either. I still feel baby kicking and playing so I know they are fine. Is anyone else experiencing this? I am 21 weeks and 6 days.