Aw, first baby jitters, gets ko na! Pressure and heaviness down there is pretty common around 24 weeks, lalo na pag tumaas na ng konti ang baby and the weight, pero since ito ang first time mo nararamdaman, mas safe talaga na mag-check lang with your OB para ma-ease your mind, basta you mention din kung may cramping or spotting, okay? One of my mum friends had the same worry at 24 weeks and turned out normal lang, pero sabi niya laking relief pagkasabi ng doctor na okay lang, kaya go na lang tayo with that peace of mind, mamsh!