Hello, I Have Been Sexually Active With Three Casual Partners

Hello, I have been sexually active with three casual partners in the past 4 months. 13 days ago, beginning the day after my last sexually encounter I began experiencing a recurring itch in the opening of the vagina and partially on the vulva. The itching is mild and not constant but has been coming and going for the entire 13 days now. All sexual contact has been oral. I am concerned that I may have herpes but have not noticed any sores yet. Is this a common showing of initial herpes outbreak?