Most man start to loose hair in the front area of the scalp, then it progress to the middle-top until the crown were it usually stops. It's called "Frontal Alopecia"(alopecia=hair loss) and it is a part of the MPB (male pattern baldness).
Your bald pattern is called "Norwood 3A" and it defines hair loss in the frontal area without loosing on the crown:
"Norwood type 3 is the lowest level of hair loss that considering as Baldness. Most of 3 classes cases present symmetrical retrogressive in the anterior temporal area without or with very low congestion and expansive to the back at least 2 cm more than class 2"
You can read more about it here:
Male Bald Pattern
and you can see some examples of patients that had a frontal loss here:
Patient Gallery
If you want to see a doctor for a full professional evaluation, fill this form:
http://www.forhair.com/contact_page.htm
Thank you