Hi Michal,
The instructions are VERY clear not to insert more than half of the balloon inside your vagina. You didn't do any damage because you only got up to 7.5 cm. If you had done more you could have caused yourself tears. You are NOT supposed to push the balloon out at the end of the exercise. IF the balloon is only inserted 1/3-1/2 then you need to hold it in all the time or it will pop out. That is correct. At the end of the exercise, you just stop holding it in, and it will pop out, no need to push. Then you place it on the measuring card with the centimeter graph lines and you can see how much you have progressed. You should use it twice a day for best results and to make up for lost time. Please tell you childbirth instructor to call me and discuss what she is telling her class. All the best, Ilana Shemesh