Our daughters each learned in slightly different ways about tampons and they NEVER used pads.
We were waiting for our older daughter to get her period. She was going to sleep away camp for the summer and had not had her first period yet. She was sent to camp with a box of junior sized tampons. One morning at camp she woke up in a pool of blood. She knew exactly what happened and what to do. She stripped her bed, changed the sheets and put in a tampon.
How could she be so nonchalant about it? I taught her how to insert them before she ever had a period before she went to camp and she practiced while she was still home.
Our younger daughter learned from her sister, so when the time came for her, she just took some of her older sister's tampons and she was off and running. No problem.
The biggest part of the problem with girls learning about their periods and what to do when they get their periods is STUPID PARENTS.
If parents (and schools) taught sexual topics matter-of-factly, the way they teach digestion, chemistry or social studies, everybody would be much better off. That's how we taught our daughters about their bodies and sex--starting when they were about three years old. By the time they got their periods, the vagina was just another opening in the body.