re: please help, twins kicking?

I know I am probably imagining, but I SWEAR I felt something two days ago. Not really the fluttering or anything like a kick, but it was more like a push out on my stomach... like pressure suddenly against the inside of it. My husband laughed and said they were fighting already.
I have only had the first initial ultrasound at 8 weeks! I am disappointed now! I want an ultrasound every 4 weeks! I am getting excited now because I am almost far enough along to know what mine are. They aren't identical, so they could be either. We are hoping for two boys though, since we have two girls already.
If you had an ultrasound you can tell by that if they are identical or not. If they are in seperate sacs then they are not. If they are both in one then they are.
I am hoping to have mine natural too. I have had problems in my previous pregnancies though, so I think it is likely that I'll have to have a c-section. But I am hoping!