Oo normal yan, mama! Eight months pa lang, lumalaki pa ang baby and everything is stretching down there, so that heaviness or pressure feeling is pretty common sa third trimester, a few of us felt the same way around that time. Pero since it's making you uncomfortable, definitely worth mentioning sa OB mo during your next checkup, especially if it comes with pain or unusual discharge, para ma-check lang properly. In the meantime, try to rest with your feet up kapag kaya, and puwede ring gumamit ng maternity support belt, one of my mum friends swore by that para sa pressure feeling niya.