'Round bubble thing' doesn't sound right to me. Have you spoken to your mom about this? You may need an examination.
Thank you so much! Very helpful.
The hymen is a thin membrane to the entrance of the vagina.
The membrane can break when a young woman does a lot of sports, and it breaks with sexual penetration.
When the hymen is broken through sports activities, the woman is still a virgin.
Virginity is lost (the woman is no longer a virgin) when the hymen is broken by sexual penetration.
The round bubble thing at the very top on the inside is the clitoris. This is where a woman will feel a lot of sexual pleasure and sexual arousal when it is stimulated.
Have a look at the web link below. It shows illustrations about your private bits, where they are and what they are called.
http://www.healthresource4u.com/hymen-definition-location-pictures-repair-broken-hymen-surgery-hymen.html