MeLuna cup developed slight crack/fold thing?

Hi!
So I got my MeLuna cup (medium, soft, ball stem) about a month ago, and I've only really inserted it a couple of times, but when I took it out yesterday it seemed sort of misshapen. It seems to have developed a slight crack on the side, except it's not really a crack... more sort of a small, permanent fold?

Has anyone ever had anything like this happen to their cup before? Is it still okay to use? It seems pretty small, so I figure it's probably okay as long as I keep it clean enough, but do you think it will develop into an actual crack?