16 weeks with MoDi twin boys!

So I’m 16 weeks and a few days,all day yesterday and today my stomach has been weird...bubbly all day yesterday and then I’ve had bad trapped gas all day today..I’m having pressure in my lower abdomen where my uterus is and sometimes little pain but nothing major. Is this normal with twins? I feel like I could fart and blow states off the map right now but it won’t come out!!