How quickly could fermentation be done?

I'll start by saying I don't have a hydrometer yet. I am going to get one but won't get a chance until this brew is bottled.

I have an irish red in a temperature controlled freezer at 68F. I used a capsule of yeast fuel and within 12 hours it was bubbling like crazy. Its now been 5 days and bubbling has really slowed (1 bubble a minute max). From other peoples experience, how quickly can fermentation finish?

I was going to leave it in the primary for 3 weeks and then bottle but I'm wondering whether I really need to leave it that long (my first brew was in the primary for 2 weeks and was fantastic).

Thoughts and opinions (not including "get a hydrometer" as I already have that planned for next trip off the island!)?

I switch to secondary once bubbling has subsided usually 1 week for an Ale.

Then a week in the secondary. Never had a problem but I am impatient and want to drink now, which is why I switched to kegging.

I've seen some ales ferment out in 24 hours, while others can take up to 5 days. My lagers tend to take 7 days or so to ferment out completely.

But since you don't have a hydrometer, I'd wait at least 2 weeks and then check the beer in a sample. If the beer is clear, and there has been no activity for at least a week, I might chance bottling it. If the beer is cloudy and has debris floating, I would NOT chance it.

fermentation could be complete for sure by now, but you need to leave it in there to clean up and clear. Most of the "active" fermentation that I saw happened almost literaly overnight. Then the beer needs to sit. You will be in better shape with the hydro, but in the mean time, just give it a bit of time. Nothing is going to be hurt to leave it for 3 weeks in the fermenter.