Hay, that sounds super uncomfortable! Parang what you're describing could be a nerve thing or muscle strain, a few of us moms actually experienced something similar during pregnancy or after, usually from how we're sitting or sleeping, kaya talaga need mo talaga i-check with your OB or doctor para ma-rule out anything serious like sciatica or something. In the meantime, try shifting positions frequently, maybe use a pregnancy pillow if you're pregnant, at warm compress helps some of my friends, pero please get it checked talaga para sure. Sending you a feel-better-soon hug!