was the same for me!this is my first child but wasnt sure what to expect, i went on hol at 16 weeks and felt what was like lots of tummy rumbling which i suspected to be bump then i got home and my weekly update said it probably was! im now 22 weeks and i first knew what i was feeling was defo the baby when i saw my tummy move, that was at about 20 weeks so im sure youre fine, could be the way baby is facing or its waking and sleeping times could be different to yours so its moving like crazy when youre asleep! every bubba is different!