Mama, yan na yan, sounds like your body is preparing na talaga! At 38 weeks, it's completely normal na mataas pa rin ang tyan mo, lalo na sa third pregnancy kaya mas relaxed na ang muscles mo, plus the mucus plug thing is a good sign na approaching na ang labor. The pains sa puso at balakang, especially gabi, ay part ng the whole pre-labor business, a few of us moms went through the same, parang practice contractions lang, pero since ang sakit ay sobrang intense na at nakakaabala ng tulog mo, better to message your OB or go in para ma-check lang talaga, just to be safe lalo na 11 years ang gap kaya medyo different ang experience mo ngayon. Hang in there, mama, you're so close na!