Mama, pelvic pain especially when you're lying down or turning sides could be many things, but kailangan mo talaga makonsulta ng doctor para malaman kung anong cause, hindi ko kaya sabihin based sa description lang. If it's really painful or may ibang symptoms, better go to clinic or emergency na para peace of mind mo at baby. A few of us moms nag-experience ng pelvic discomfort during pregnancy, pero it's really best na marinig mo from your OB kung normal lang o kailangan ng care. Sending you a hug, sana mabilis makakuha ng appointment!