Ay mama, that sounds uncomfortable! Please go see your OB soon, hindi lang para sa peace of mind mo, kundi importante rin na i-check nila kung okay ang baby at how baby is positioned.
Marami sa amin mga mumsh, especially around 20 weeks, nararamdaman yung strong movements na parang nakakahirap, pero better safe than sorry talaga when it comes to pregnancy, your doctor needs to rule out anything serious. Kaya go na, don't wait!