Menstrual Cups - Divacup, Mooncup, Instead, Lunette, Miacup

Hi, coleagues! I'm so glad to become a cup user and this is my first trial. I'm 30 and had a childbirth by cesarean, and chose small lunette (diane) for easy start. I reinserted cup for several times already and it becomes easy. My problem is leakage.
Does it mean i need a bigger size to try? But i have suction with the small one and it does not migrate.

 I just read an article on the new airport body scanners that suggests that they can see menstrual products, including tampons.  I am wondering if they can see menstrual cups as well.  I'm concerned that if I fly with the cup I will be subjected to increased scrutiny  --  I can't imagine the TSA is very sympathetic to those who put "strange" objects in their vaginas!  Does anyone have some facts on this?  Thanks!