Really nervous and worried

So at my most recent ultrasound this past Friday the technician doing the test said more than once that she was looking at the stomach but when the doctor came in he said he didn't see it at all and now they are having me come in for a new ultrasound and consult to make sure everything is ok and people keep telling me not to worry but that's not possible!!! I'm so scared something is wrong even though I have done all the blood work I can do even the harmony test and everything has been perfect until now!!! I'm just freaking out!!