Is there a way to tell if you have had mononucleosis in the last 1-3 months? i had a test run but it is unclear to me.

IgM: If your IgM is high or monospot is high, both are indicators of recent or current infection. If only IgG is elevated then that indicates a past infection.

Yes and no: Most traditional mono is caused by the EB Virus. Blood drawn during the first 3-4 wks can show a high IGM level to EBV in the early stage of the infection. As the weeks pass the level of IGG to EBV increases and IGM fades, you can have a positive IGG to mono months or years later. Without knowing the test you had run, its hard to comment.