Aw, first baby jitters, totally get it! Balakang pain during pregnancy is super common, a few of us moms experienced it around second at third trimester, usually dahil sa weight at hormonal changes, pero best talaga to check with your OB to make sure it's nothing serious, kasi they can give you proper exercises or support recommendations na safe para sa baby mo. In the meantime, rest as much as you can, avoid heavy lifting, at pwede mo try pang warm compress or pregnancy pillow para mas comfortable ang sleeping position mo. Alagaan mo ang sarili mo, mama, you're doing great!