I've got the Adult Content thing turned on for the moment, but I'm not much liking the idea so I think it'll be off again at some point. Realistically, I'm much more concerned about potential future employers finding my journal than underage kids. Can LJ set up a filter for that? :D

No comment on the Tampax, but have you considered a menstrual cup? Much more comfortable than a tampon and cheaper and more environmentally friendly too! menstrual_cups is a really good resource, if you're interested.