Ay alam ko yan, normal lang talaga especially pag first time mom ka! Pag nakahiga ka, gravity pulls down so ang tummy mo talaga mukhang mas malaki or mas swollen, lalo na pag gabi or after eating, nakita ko yan sa sarili ko at sa iba pang mum friends ko rin. But just to be safe, mention mo sa OB mo next checkup kung paano exactly ang feel, kasi kelangan ninyong sigurado na normal pregnancy swelling lang ang nangyayari at walang complications like preeclampsia. Most likely it's just the position and how fluids settle when you're lying down, pero better safe than sorry with pregnancy stuff, diba?