Experiences?

Sorry for the long post.

okay. So, my oldest son is only 6 months old. I am 10 weeks 4 days with baby boy number 2. This is my 6th pregnancy. However, my uterus is very high like I'm even feeling the baby's flutters above my belly button. No it's not gas I can easily tell the difference felt my 6month old this early on and doc confirmed it was him moving. I can feel early due to my stature. I'm very underweight due to a hyperactive thyroid. Anyway my question is, isn't my uterus still supposed to be below my bellybutton or do uteruses stretch faster after your first full term baby or could it be because they are close together? I just think it's really odd that it's already that high. At my previous appointment i did not get to see my doctor, I only had an ultrasound i had a small hemorrhage but they didnt seem worried could that stretch my uterus more? I get to see my doctor on the 29th and will ask her all of this as well but just want to know y'alls experiences.