From 2 days i am feeling pinching sensation around navel area..this happens only for few seconds..sometimes to left of navel sometimes right sometimes to bottom of navel..only pinching sensation..no pain.. The pinching sensation lasts only few seconds and happens after few time..this is my first pregnancy..i have just entered into 7th month..till date each and every test and usg is normal...plz tell me the reason of this pinching feel