Can mono affect your menstrual cycle?

Yes it can: Virtually al type of infections have the potential to "mess-up" your cycle, but often minor/short-lived occurence. Mild mono is not likely to do that, similar to the common cold you get, but significant mono/or any illness can throw your cycle off. Many medications do so as well. Rapid wt loss/gain, extrenuous/prolonged exercise can do so as well. Consult doc if persistent. Good luck.