Aww sayang, that shooting pain feeling is actually quite common around 15 weeks, a few of us mums experienced it too and it's usually ligament stretching or baby growing, but since you're pregnant better check with your doc just to be sure everything's good with the baby and cervix okay. Rest when you can, don't overdo the walking in one go, and drink plenty of water! Doakan you and baby sehat-sehat sampai lahir, insyaAllah everything will be smooth sailing for you