Why did I get breakouts of small pimples?

It's been a little less than a week. I've been getting small pimples around my body. From my chest to my back to my arms and legs. None on my face. Also some on my neck. I havn't gone to the doctor. Can anybody tell me whats happening? Is it herpes?? Because some girl I think has herpes(she has had a bunch of bfs.) tried to give me a hickey.