Situation You ate some mezonot. It might be more than 72 minutes since you finished eating but you are not certain.
What To Do Doubt about a blessing (safek bracha) does not get a blessing.
Note You may not eat one of the Five Special Fruits in order to say the after-blessing of al ha'eitz and include al ha'michya. You could eat fruit and say the al ha'eitz blessing, but you may not include mezonot food in the blessing by adding al ha'michya.