What will be, will be

I am 37 weeks pregnant, very large, very uncomfortable, very tired and very nervous about our sonogram tomorrow.
Last week I went in for my routine weekly checkup and ended up at labor and delivery. They just wanted to do some extra monitoring on our little gentleman and his heart rate. Everything ended up being all good but since that evening I have been nervous that things will not go right. Just that overly protective mother feeling. I am not a negative or a pessimist but it is hard for me, specifically me, to get over a trip to labor and delivery a month early. I guess since i am not an incredibly "go with the flow" type person one event throws me a little for a loop!
So that being said, I am a little nervous when they asked that we do an ultrasound this far along. I know the doctor just wants to check the size of our little gentleman and the amount of amniotic fluid. My belly is measuring on the large size, about 1.5 weeks bigger than my due date. My fear is that they will say, "Its time to have this baby" and neither the baby or I will be ready.... I guess I am just trusting that whatever happens is the way its suppose to be.
*** I AM NOT SAYING ANYTHING IS WRONG! Just to clarify, it is most likely my paranoia.***