Mej normal yan sa 13 weeks kasi lumalaki na talaga ang uterus at nag-stretch ang ligaments, pero mas safe kung i-check mo talaga sa OB mo para ma-rule out kung hindi lang round ligament pain, ate! One of my mum friends also felt something similar around that time and the doc said it was the ligaments stretching, pero sabi niya importante pa rin i-confirm to be sure, lalo na kung malakas or may accompanying symptoms.