WYeast Belgian Strong Fermentation Length??

I have a belgian with an OG of 1072 that has went like gangbusters for about 5 days, and seems to have petered out.. Could the yeast have gone through all the sugars that quickly?? My temp started at 64 and slowly worked up to 70 over these 4 days (as the recipe called for)..

I know the only realy way to know if the hydrometer, but this to fast given the OG. Any idea's?? If this gets stuck I have some SafAle05 I can pitch to help continue but the smack packs are unavailable at this point.

Thanks

You have to take a reading. Otherwise we are just guessing. I'd had beers finish primary fermentation in 3 days with London Ale yeast....You are probably fine...

It's not unusual at all. Just relax and take a measurement but don't be surprised if it tastes like **** this young.