Aw sis, ang sakit ng likod at puson during pregnancy especially when baby's low talaga super common pero grabe na talaga if it's that intense even with rest! Since your doctor already checked and confirmed it's just baby's position, siguro okay lang pero honestly if the pain isn't improving kahit nagbedrest ka na, worth getting a second opinion or asking your OB again kung may physical therapy or safe stretches na pwede mong gawin, kasi sometimes lamig or tension lang talaga but better sure na hindi may iba. A few of my mum friends swore by maternity pillows and sleeping on their side with knee support, plus some relief from warm (not hot) compress, pero ikaw talaga ang makakaalam best kung ano tumutulong sa iyo. Hugs, mama, laging normal ang back pain but your comfort and peace of mind matter din, so don't hesitate to reach out to your doctor ulit if kailangan mo.