Movement?

What do baby kicks feel like around 18 weeks? I've not felt the baby before today and in the last hour I just keep feeling something in my Tummy moving around. It's too low for something in my actual stomach and it doesn't feel like gas.... The only reason I'm not sure if it's the baby is because I haven't felt her yet and suddenly it feels like she's jumping on a trampoline in there, it's not hard but it's a lot of movement (if that's what it is)