My minds everywhere

I'm a first time mom and I just feel so overwhelmed with everything at this point... at 37 weeks I was scheduled an ultrasound for my baby's measurement because my Dr believes I'll be having a big baby and suggested I'd keep C section as an option .. I went to my ultrasound appointment and I measured a week more (38 weeks instead of 37) i understand that its not a bad thing to be a week more and what not but that still got me thinking maybe my baby will be big and I wouldn't want c section because I want to have more than 3 kids .. i haven't had my appointment with my dr too see what he says about the weight of the baby and the whole c section delivery anyway I went to the hospital earlier because of cramping and the RN who checked me and all told me I was dilated 1 cm and that my uterus is high as well...which i didn't understand if that's a bad thing or good thing ... and i know im not going to dialate from one day to another fast but ive been 1 cm for two weeks now anyways she also asked me if my Dr was concerned of the size of my baby and I let her know that he was and it just got me thinking like okay if she's saying it as well then my baby might b big... im 38 weeks and I know I'm over thinking everything and just need someone to reply with there experience and how great everything went for them so I know everything is going well with me lol thanks in advanced(: