A woman I worked with was already going through menopause and because the baby was so far back, she was 7 MONTHS before she found out and only knew because she went to donate plasma. Babies will wedge themselves anywhere they find comfortable!
Baby changes sides all the time... If baby is facing inwards or gone towards ur back it will feel like ur stomach has shrunk... If u r concerned u should go to hospital.... I hve read abt one the lady on internet... Her daughter was sleeping right at the back which caused her tummy to look very small... So tht might be the case....
I don't know of that's normal? My belly changes shape depending on where bubz is sitting. If you are worried I'd see your doctor.