My girl has an itching below on the vulva. She has no discharge, no odor, but she has some pains in her pelvics area. Is this a yeast infection, and if it's a std what are the usual time spans for symptoms

Well your "girl" or vagina could very well have a yeast infection. It does sound to me as though you may.

As far as STDs, it is all very different for every infection. Some have no symptoms at all, some are symptomatic from the get-go. All of the symptoms are different.

So, it is best for you to go to your doctor and have this checked out. If it is a yeast infection, it is a simple fix. If it is an STD, you will have to be put on antibiotics.

I agree. And also-pain in the pelvic area in the absence of the menstrual time should lead one to consult a gynecologist.