Could my baby be sucking her thumb in my belly?...29 weeks pregnant?

I haven't felt much for hicciups...mabey once or twice..but I feel this un rythmectic..kinda like a hiccup feeling, could it be my lil girl is in there sucking her thumb? I caught her in my ultrasound sucking her thumb at 18 weeks...I was a thumb sucker as well...so bad I had braces lol it seems since I've been feeling this she's been mostly head down..and kicking a little less..what do u think?