Am I feeling movement?

Recently I've been feeling very frustrated and down because I feel like I'm the only one in the August 2016 babies group that hasn't felt movement yet. I'm 20 weeks today and I can't say definitively whether or not I've felt anything yet. For the past week I've noticed what feels like muscle spasms in my lower tummy. I'm confused though because I've also been having gas every day so I don't know if these feelings are gas or the baby moving. I've never noticed these feelings before so that's what makes me think it might be the baby. What do you guys think? What did it feel like when you first felt your baby move?