Kids calling me by my first name

I know this is a stupid thing to be upset about, but my two year old and three year old recently started calling me by my first name. My 3 year old started about a month ago, and this week my 2 year old started. I know it’s dumb to be sad about it, but it was so cute when they called me mommy 😭😭😭 is this just a phase? I correct them but they don’t stop lol