Movement 22w5d

Im 22w5d. Is it normal that my baby girl was moving a lot last week and now her kicks are not very often at all and when she does kick its not as strong as it was a week ago?? It is really starting to scare me. When I lay on my back it looks like she is not growing, she looks the same as a couple weeks ago. My knees and legs have been very weak and hurtung. I don't know if that has to do with anything. I am just really scared. Any advise?