I was flying home and while at cruising altitude of something near 30,000 feet I felt an odd pressure from my cup. I went to the lavatory, removed the cup and put it back in but the thing would not "pop" fully open to save my life. I finally got it mostly open and just dealt with the slight misses since it was only the second day of my period it wasn't a full on flood.
However, I'm assuming what happened was the pressurized cabin created an issue with my cup's suction, which caused the initial discomfort. The resulting in ability to "pop" properly could be for the same reason, the cabin pressure.
I was just curious if anyone else has ever experienced this before?