I’m scared please help

I am Pregnant with my second baby. I stared feeling the baby kick at 11 weeks! It was confirm during an ultrasound where I saw it move and felt it move. Regardless. I felt it constantly for weeks. I am 17 weeks now and the movement has really slowed down. It stopped about 2-3 weeks ago. The movement is very minimal. I don’t even think I’ve felt my baby move at all today.... is there any explanation for this!? Why would I feel her move so much so early and now when she is supposed to be growing and bigger I barely feel anything. I’m just scared. My first daughter has a muscular disorder and didn’t move a lot so I’m so scared this is happening again to this baby. I was sure it wasn’t bc of the movement i felt so early. Please help me.