How long after being infected with will you get an outbreak?

Okay, I just had a baby 2 months ago! I had a natural/l deliverly! I have two other previous healthy l deliveries! Here's my question! I had a schelduled 6 week checkup for a Monday, two days before that I had unprotected with my husband of 7 years! Note, he is the only person I have been with ually for the past 7 years!!! When I went to my checkup, I had a red patch of a cluster of bumps around where you shave. I thought it was maybe a irritaion of some sort, all though I havent shaved since before my delivery! Anyhow, based on my ob's visual inspection he said it was definatley HSV, and asked if I had in the past 21 days. When I answered yes, he said well thats when you were infected! He took a culture but the culture came back negative! He said he doubts the culure so I have blood work schelduled! My question is, would this mean my husband cheated on me, and he just got it and just gave it to me? Also could he of had it for 7 years and I just now get it? I hopin for a negative blood test as well! Its just odd how we had and it showed up basically in 2 days!! What do you guys think??