Hi dear, at 35 weeks it's normal untuk perut mengeras (that's Braxton Hicks contractions), tapi since you're also having heel pain, fullness, and lower back ache, better check with your doctor to make sure everything's okay lah, these things together are worth getting checked out, especially since you're in the final stretch. A few of us mummies had similar complaints near the end and it turned out to be nothing serious, but peace of mind is important! In the meantime, rest as much as you can, wear comfortable shoes, and try warm compresses on your back, hopefully your doc will give you some relief tips too.