Long fermentation with BBP

I brewed a Bourbon Barrel Porter on 10/16 and put in the primary fermenter. Fermenation kicked off strong and lasted for 2 days and then went to about 1 or 2 bubbles a minute. After a 2 weeks I transferred to a glass carboy for finishing the fermentation. After a couple of days in the secondary the bubbles went up to 6-10 bubbles a minute and has continued for the last 4 weeks in the secondary.

My questions are:
-Is this normal for something to kick off again after transfer?
-How much longer should I wait before adding the Bourbon? I dont want to kill off any active yeast by adding the bourbon.
-Should I take a gravity reading and if its below a certain reading should I go ahead with the bourbon? What reading is considered okay to do this.

I welcome anymore advice you might have with this beer. This is the first time brewing a high gravity.

Thanks Mike

Which yeast are you using and were the fermentation temperatures steady? Some yeast require a long time to finish. What is the temperature of the beer in the secondary?

SG readings would have been best before racking. Take a SG reading and take another in five days. I would recommend the SG readings taken further apart than normal to better judge what is happening. Four more weeks of activity isn’t normal.

Hold off on the bourbon in case an infection has taken over your beer.