17 weeks. Need advice from other moms.?

I turned 17 weeks on friday June 24th. For the past few days i've felt alot of movement and i think kicking. I know it isn't gas because i have that too and i can feel the difference. But should i be feeling alot of movement right now or am i just thinking it?? I'm also not very hungry. I mean i get really hungry so i eat and get full quickly and then five minutes later i get hungry again. Any way to help that? Also. If i lie on my stomach which is actually the only way i can fall asleep and it's comfortable i can feel a pulsing. Is it coming from baby or from the veins and arteries in my stomach? It's very strong. Sorry for all the questions i'm just worried because this is my first and i want advice from experienced women. Thank you.!