Lots of pressure when I sit.

When I sit down, I will occasionally get a ton of pressure in my uterus. And I mean a ton. I have to sit down very slow, or it will be a sharp jab. I'm 8 weeks 5 days with twins. I see new doctor on Wednesday. Is this normal? Or is this something to bring up? I don't remember a whole lot with my first pregnancy. And plus, this one is very different lol. My 'stretching ' pain is pretty much gone. This is the only pain I have now. I guess I'm just being a worry wart, but I'm wondering if any of you, single or multiple pregnancy have experienced this.