Aw mama, that side pain under the breast especially when you're full or lying down can be a few things, sometimes it's just the ligaments stretching, or gas, or even how baby is positioned if you're pregnant, pero honestly kailangan mo talaga patingin sa doctor para ma-check properly kasi hindi dapat mag-alala ng basta-basta! One of my mum friends had similar pain and turned out it was just round ligament pain na tumaas with pregnancy, pero may ibang cases din na something else, kaya better safe than sorry talaga. Mag-book ka na ng checkup, ha, para peace of mind mo at para alam natin exactly ano ang happening.