Movements slowing down..

I called my OB and I'm waiting for a phone call back. I'm almost 37 weeks.. My baby moved yesterday, but not as much as normal. I've never been able to do the count kick because he's either non stop or doesn't move alot. He's moving and kicking, just not as much as normal. I guess I'm freaking out because I thought I was leaking fluid, which the test came back negative and ultrasound looked fine a couple of weeks ago. Did your babies slow down at the end?