Your bariatric surgeon is your best source of information about pregnancy and birth control and will be able to advise you according to your individual circumstance.
The period between surgery and weight stabilisation is considered as a period of starvation. It is not advisable to become pregnant during starvation, despite the fact that the foetus has priority over the mother with regard to food. Should you nevertheless get pregnant, it is advisable to remove all the fluid from the balloon. You should wait until your weight has stabilised before becoming pregnant.