Because as trials go on scientists discover more information and alter the theories and that is why they are referred to as a "theory" instead of a scientific "law"
the bond between two water molecule is hydrogen bond.
It is located At the umbilicus
At 20 weeks' gestation, the fundus can be palpated at the
umbilicus. A fundus of 12 weeks' gestation is palpated at the symphysis pubis.
At 16 weeks' gestation, the fundus is midway between the symphysis pubis and
umbilicus. At 36 weeks' gestation, the fundus can be palpated just below the
ensiform cartilage.