HI, thanks for using healthcare magicTubal ligation
procedures for birth control are usually very effective. During pregnancy
the hormone HCG
is released, this can be detected normally from day 12 to 14 past conception and your pregnancy test would have been able to pick it up if it was present.
The flutter sensation that you are experiencing may be related to either the intestines or the nerve
supply to the muscles or skin of the abdomen.
I hope this helps