It depends. Some people have normal blood work even when flaring. Mine was only marginally above normal when I was in bad shape (busily forming a peri-anal fistula). So for me, blood work doesn't tell me much. But it's still good to have a base-line before you change your diet/treatment as you can still see if there is a general upward or downward trend over the course of a few months.
Calprotectin has been REALLY useful for me for this reason. It goes up or down A LOT depending on how I'm doing, and numbers go up well before a flare for me, so I have time to correct things. It's not feasible to do a colonoscopy every few months, but this way you can get a good idea if the state of your insides is getting better or not..
I wouldn't NECESSARILY worry if the numbers don't start going down right away, healing takes time...
I wish you the best of luck, I'll be following your thread!