What makes you think that you had H1N1? Do you still have flu symptoms? Are they getting worse? Or did you just overwork your body before it was completely healed from the flu and now you are feeling fatigued? Flu varies from person to person . . . for me, it comes on suddenly, I have 3 very ugly days and then 3 or so getting over all of the symptoms but then I am fatigued for the next week to 2 weeks as my body recovers. Don't forget, depending on your physical health, the body uses up a lot of resources fighting viral and bacterial infections.
If you are concerned, then see a doctor . . . .I am not a doctor but in the absence of any other condition or worsening symptoms, it sounds like you overtired your body . . .take care, kc