Anak, please go see your OB right away, ha, especially pag ang sakit ay malakas or may bleeding. Better safe than sorry talaga, 13 weeks pa lang kayo! Maraming pregnant mamas ang nakakaranas ng cramping or ligament pain, pero importante na ma-check ng doctor para ma-rule out kung may ibang dahilan. One of my mum friends had the same worry at nag-alala siya, pero pagkatapos ng check-up ay okay lang. Just don't wait, call your OB mamaya na. Sending prayers your way!