When you say you had oral sex, did you give, receive, or both? Was this a couple of months ago?
1 - You can have symptoms anywhere in the area that boxer shorts cover. Typically, you get symptoms at the point of infection, wherever the virus entered your body, but it can be anywhere in that area.
2 - Usually, you get symptoms within 2-12 days, but it's possible that you could get symptoms later.
3 - If this is a brand new infection for you, it would be unusual for you to get sores that would go away in a week with no pain, fever, etc.
If you just have spots or bumps, this is not herpes. Herpes are blisters or sores. It's not bumps. If you are unsure of what you have, you need to see your doctor.