Mommy, that sounds like it could be sciatic nerve pain, super common sa third trimester dahil sa weight at position ng baby, but honestly, UTI symptoms can overlap din kaya better to check with your OB para sure, lalo na at 36+ weeks ka na! A few of my preggy friends had similar pain na nag-ease after prenatal massage or pelvic exercises, pero iyong situation ay magsosound talaga need ng checkup dahil hindi ka makatulog na at ang sakit, that's not something to push through lang, especially malapit na labor mo.