In Nega'im 3:2 -- and also Moed Katan 7b at the bottom -- we learn that a Kohen doesn't examine a nega during teh chagim, or chol hamoed, because it may reduce the joy. OK, that makes sense. Then, they both say: and we don't examine a chatan during the days of sheva brochos. For the same reason. What about the kallah? -- Sholom