Welcome to the forum.
Imiquimod (Aldara) commonly causes irritation, including various combinations of redness, soreness, and sometimes overt ulceration of the treated tissues. In fact, that's how it works against warts -- causing inflammation in and around wart tissues. And herpes doesn't cause redness as it's only symptom. For confirmation, you should discuss this with the doctor or clinic that prescribed your imiquimod treatment. But from what you say, I see no reason to be concerned about herpes.
Regards-- HHH, MD