Has anyone found out they were pregnant late due to negative tests?

Have any of you experienced something similar to this? I’ve never missed a period before and I’ve never been more than a few days late. I’m currently 11 days late. I know this for certain because I keep track on an app. I took a test today in the afternoon which was negative. I’m not anymore stressed than usual. Nothing else different. I’m just so confused because I’ve never experienced this before. 🤯🤯🤯