Given the sequence of events you describe, chances of pregnancy are pretty remote (would say there is no chance). Yes, prolonged two week mono infection can delay periods. Also, your stress can delay it. So, if you do not get periods in a weeks time, take a pregnancy test and see. In all probability it will be negative. You will then need to consult a doctor for medications to bring about the periods if they delay beyond 10 days. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.