My monthly cycle is usually 28/29 days. I was estimating my period to arrive for tlast Thursday. I wasn't worried when it didn't come on over Thursday or Friday or even Saturday or Sunday. On each day I thought it will be here the next day. We are now half way through Wednesday and still no period.
About 3 years ago, I went through a very stressful time. I went from a regular 28/29 day cycle to 32/33/34. It did settle down eventually. I do think stress had a lot to do with it then. It was unfortunate. All the stress I experienced was beyond my control - work, family, other issues.
It was like clockwork since it settled down.
Here I am now about a week late and gone into cycle day 35 of what is usually a 28/29 day cycle.
About 3 weeks ago, it was the end of the heatwave, I struggled during the heatwave, I had a bad week in work, it was so stressful and intense. As soon as I finished a 10 day very stressful work stint, I became sick. It wasn't covid. It was diagnosed as a kidney infection. I was on antibiotics. I also had other stresses.
Definitely not pregnant unless it was an immaculate conception. Me and my partner have the most driest of sex spells with only about once or twice a year and even at that it's awful.