I Have Faint, Reddish/purple Lines On My Stomach Near My

I have faint, reddish/purple lines on my stomach near my belly button. There are only 4 or 5 and they are vertical and only on one side of my stomach. They are only about 1/2 in long each. They don't itch, they aren't raised, and they don't hurt. I am not pregnant, but they seem like mauve stretch marks? Thanks!