Hey mama, normal lang yan sa pregnancy, especially around 15 weeks when everything's stretching and shifting inside! Pero since it's something you're worried about, best pa rin na i-check mo with your OB just to be sure, better safe than sorry, diba, para makakuha ka ng peace of mind. A few of my mum friends had the same concern and their doctors assured them it was just ligament pain, kaya wag mag-alala masyado. Try to rest when you can at magpainform sa doctor kung paano exactly ang sakit para ma-address niya properly. Take care, mama!