Alam ko yan, madalas na yan sa pregnancy especially around 9 weeks kasi lumalaki na ang uterus mo at nagsisimulang mag-adjust ang ligaments mo, a few of my mum friends felt the same thing and super worried din sila! Pero kung meron kang severe cramping, heavy bleeding, or parang hindi normal ang sakit, definitely check with your OB agad para ma-ease your mind, okay? Ang sudden tightening ng puso sometimes just Braxton Hicks or ligament stretching, pero mas safe na consult lang so walang worry ka.