Odd cycle this month

My cycles usually last between 28 and 30 days long and I capture peak every month too. This month my cycle lasted 26 days and never captured my peak for the first time in 5 years. I have been stressed last few months and this is adding to it further. Im 35 years this year and after 5 years ttc with only ever getting a chemical, just feel this is possibly another spanner in the works. Has anyone had a random short cycle? Could it indicate a problem? Thanks in advance