Hi mama! Ay, ang sakit sa puso area at left side ng belly can mean a lot of things, hindi lang pregnancy-related, kaya please see your doctor soon para ma-check properly, okay? Especially important if it's sharp pain or hindi ka comfortable. One of my mum friends had similar and nag-alarm siya sa OB, but turned out okay lang, pero better safe talaga kaysa sorry. Tawagan mo na ang clinic mo, or if sobrang intense, go to the nearest emergency room na. Take care, ah!