Snapchat 1, Serena Williams 0. The tennis player admitted yesterday that her post on the social media app announcing her pregnancy (which she quickly deleted) was a mistake.

In Vancouver for a TED Conference, she said she’d been using Snapchat to track her pregnancy when the photo accidentally got published. “I have this thing where I’ve been checking my status and taking pictures every week to see how far along I’m getting. I was just saving them (for myself). I’ve been so good about it, but this was the one time it slipped.”

Serena is expecting her first child with fiancé Alexis Ohanian. Here’s a more official pregnancy announcement, which she posted on Instagram.