I am 8 months pregnant, and I am hearing some popping/cracking noises in my belly every now and then. They sound like someone cracking their fingers underwater, I do not experience pain when I hear this, it just sounds odd to me and I would like to know what it is from. My theory is the noise is my uterus growing?

I think your baby may be having hiccups. Babies do you know. They feel to you like rhythmic "burps" and they will go away after awhile. Unless you are leaking amniotic fluid or having any other symptoms, this is perfectly normal.