2 days late but negative tests

I should have gotten my period Wednesday, Thursday at the latest. I track here on the app and have been on time (if not a day early) for the past 5 months. The last two days I have been feeling nauseous, especially after eating lunch. I took a test Thursday night and Friday night and both were negative. I've heard that sometimes it's best to test when you first wake up so I did this morning and still negative. I'm so confused! Has anyone had trouble getting a positive test at home?