I had mono really bad about 3 weeks ago and missed two weeks of school and finals, I had my period a week before I got sick. I was sick with mono and strep and took penicillin and antibiotics. I also lost 10 lbs while being sick which also included throwing up and having a high fever. My boyfriend and I are sexually active but we don't have sex, so we are just paranoid, but could I miss my period from mono?