It could be either. How many do you have? Is it wide-spread over the one side, or more focused in one area? Did the bumps appear shortly after you shaved, like within several hours or a day?
Have you had a recent possible exposure to herpes?
If it's more spread out over the area you shaved, it's more likely to be razor burn. Don't discount that, though - those can get infected and you may need medical treatment. If the one spot doesn't heal soon, get it checked.
If the symptoms appeared shortly after shaving, that lends itself to being razor burn, too.
Don't hesitate to get it checked by a doctor. A doctor can look at it to see if it's razor burn, folliculitis (infected hair follicles), or herpes.