Little thump?

Second time mom, 15.5 weeks. Haven’t felt any “movement/flutters” that I’ve noticed. I was laying on my back and felt a little what seemed to be like a thump. Honestly idk if my baby is down low some or near my belly button by now but where the circled area is is where I felt a little thump. Does that seem about right to feel something right now or was it just something else? Didn’t feel anything from my first until way after 20 weeks that I remember. What do you think? I’ve been so impatient to feel something this time.