Baby not moving much


I'm 37+5 And for the past couple days I've had a cold. He was moving like crazy yesterday, but today I took sudafed and benadryl (okayed it with my ob) And also took a warm bath. Ever since I got out of the bath I haven't felt him move at all, and that was about an hour ago. Should I be worried? Do you think the medication made him drowsy or something? I'm just really paranoid now and don't wanna take it anymore.