Genital herpes can present with physical
symptoms within a 2-20 day period. If the only symptom you are experiencing is itchiness, than its more than likely it's either your imagination / some form of dermatitis (eczema) / jock itch, etc. etc...
Again, if your only symptom is itchiness, its best you DO NOT itch, but monitor your symptoms. If redness and inflammation appear in your genital region, and or any lesions, bumps, blisters, cuts, ulcers, etc...