What is going on with me?

Ive always had a regular period! We just started TTC. My period was due yesterday (Friday). I took a preg test Wednesday it was negative. Usually AF comes like clock work. I feel like she's coming but nothing has come. This has never happened to me! Have I stressed myself out so much that I made a period not happen? I've seriously only thought about getting pregnant since we started! I'm so worried now I can't sleep. Anyone know?