This is going to sound bad, but I just want to know what you think...?

can't answer all of your question but i can answer some.yes sonograms and doctors can be wrong.with my last child i found out at the beginning week of november that i was pregnant by using a home pregnancy test,it had already been about 10 days from missing my period.didn't go to the doctor until mid late december, they told me that i just conceived which was bull and i knew it.i ended up carrying until september before they finally induced me.do the math that's 10 months!they went on ultrasound pictures and were wrong.i can see why your worried i know i sure was.but sonograms/ultrasounds are not 100% they do THEIR time by measuring the child in the picture which is not a great way to do it because every child grows differently