Periods-tampons

So I'm on my second period and I want to use tampons. My mum won't let me. I think she won't let me because of what happened to a family member or all the myths that are floating around. I want to get them because they are way more comfortable than pads and I don't want to worry about swimming. I've already bought tampons and sneaked them into the house easily, now I want to get tampax pearl and they come in a much larger box than the ones with no applicator. So how do I sneak them in and how do I buy them (go to the shops without being suspicious)??