Two weeks in primary will be more than enough with a regular beer fermented with healthy yeast. If it's in glass and has darkened that will tell you for sure. Honestly it's been a while since I took an OG and I only use the hydrometer to 1)make DAMN sure a big beer is done and 2)get a taste from the sample cylinder. I've yet to try Celis but if it's a traditional wit you'll be fine. If you've been brewing for two years and trolling here for a while you'll know if it's done without the hydro.
Looking forward to brewing some beer