Blood work timeline after Da Vinci Prostatectomy... Months???

My dad had the Da Vinci prostatectomy on Sept 5, just about ten days ago. The pathology report came back and shows that the cancer was localized, but that it was really close to the bladder.  Not to mention that the tumor was quite a bit biger than they originally thought it was. His dr. seems to think that he doesn't need to get blood work done for another 4-5 months. Does this seem like an extremely long time to wait? Originally they had recommended blood work within 6-8 weeks, so the change to 4-5 months seems rather lengthy.  The physician has not recommended any chemo or radiation therapy.  Any advice is welcome, as I am still feeling pretty unsettled about this. Thank you!