Uy, yan ang normal pregnancy thing talaga, mommy! At 4 months, lumalaki na ang uterus mo so feeling mo parang swollen or heavy ang pelvic area, lalo na kung mahabang standing or sitting ka. A few of us moms experienced the same, one friend said parang may pressure lang siya down there, which freaked her out pero totally normal daw. Just make sure you're resting enough, wearing comfy bras and loose clothes, at hydrating well kasi tumutulong din yan. But para sure and para may peace of mind, do mention it sa OB mo sa next check-up okay?