Allergic to Wasp Sting?

Last week, I got stung by a wasp. It left this kind of doughnut looking bite, with a white ring and a red dot inside. It hurt pretty bad for the first two days, but now it just really itches. Now it kind of looks like a really hard mosquito bite. My dad said that he thinks I'm allergic because his stings never itch for this long. Am I allergic if the itching is the only symptom?