Personally, I like it when people laugh a lot. But if it's a nervous laugh after you speak, it could be a desire to be agreed with, and if it not agreed with a laugh can make it as inconsequential as a joke. So, 30 days to make or break a habit. This habit won't go away overnight. Give yourself a little time to eliminate the laugh by consciously catching yourself before the laugh comes out. Maybe smile as a substitute.