Hey mama! Normal yan during pregnancy, lalo na sa second trimester, a few of us felt the same sharp twinges sa puso down to lower belly, parang ligament stretching lang as baby grows. But since you're 5 months and it's coming and going, best to mention it sa OB mo next visit para ma-check lang if ligament pain lang talaga or if kailangan i-monitor; hindi masama maging sure, especially first pregnancy pa lang. Drink lots of water, rest when you can, at don't worry too much, most likely normal lang yan, sis!