I think I'm going crazy!!

I'm 17 weeks pregnant but haven't had an ultrasound since I was about 8 weeks, I haven't felt any movement yet either. I haven't had any problems with cramping or bleeding at all since I miscarried in April, but for some CRAZY reason I just have a feeling there's no baby in there! I know it's sounds stupid but I just can't help it. I go Monday for my ultrasound and genetics visit so I guess I will find out for sure, but until then I'm gonna go nuts!