I'm pregnant with my second and I'm 20 weeks and I heard the same with my first, it is the baby and you can hear it because it's moving but you can't feel it yet as your still very early
I'm pregnant for my first time (19 weeks). I wasn't sure at first but I would feel some bubbles that usually were followed by gas. Last week I noticed the feeling lower in my uterus area and no gas followed. I went to my doctor last Friday and he said yup, I have a very active baby and I'm feeling her move :) hope that helps! As for sounds in your belly, I've not heard that that's a thing but I keep getting told every pregnancy is different.