I brewed a Bourbon Porter a few months back and all the fermentation happened in the first few days. Check you S.G. a couple of times over the next week to verify it's still going down. Time in the secondary is needed to further "age" the wort. I added the bourbon-soaked oak chips about 3-weeks into fermentation and then bottled about one week after that (total of 4-weeks of primary/secondary fermentation). Just cracked a bottle yesterday and it tasted great. I've heard it gets much better with age, so I will try the next one in a few weeks.