Not feeling movement

I'm 17 weeks today and freaking out a little cause I haven't felt baby boy move. I thought I had been feeling little flutters here and there since about week 15 but, over the course of the last week I haven't really felt anything. This is my 2nd pregnancy, so I know what I'm feeling for. It makes me nervous because I read on here a couple days ago about someone who was about as far along as I am went for her ultrasound and baby no longer had a heartbeat. Of course, ever since my mind has been racing. I dont go back to the OB until next week. Is there anything I can do to give myself some peace of mind? Perhaps make baby move around so I can feel the flutters again?

*Yes, I know some women dont feel baby kick until after 20+ weeks but I've already felt baby move which is why I'm concerned now that I havent felt it anymore.