If your temp is lower than the high 60'sF your yeast will be sluggish. Most likely the case being winter although I see you're in Texas. Your yeast may also be old, which will cause it to take longer to get up an running. There could be many reasons that it's still bubbling, but after a week I think that it should be. Don't worry about the time, just let it do what it has to do and it will eventually stop. Wait until you get less than a bubble per minute or so before thinking about racking to a secondary. Really nothing to worry about though.