Ovulation date is supposed to be this week...but OPK is negative...?

It could be either. I would bet that you are either going to ovulate late or you may not ovulate at all this cycle. Typically, when you have something traumatic happen to your reproductive system, you are prone to an anovulatory cycle (not ovulating). It's fairly normal. I had an ovarian cyst rupture and I don't think I ovulated for 1-2 months. Maybe you're just ovulating late though. If your cycle is 33 days, you should ovulate around CD 16 or 17, which would have been a little less than a week ago. Keep in mind too, that you could have just missed your surge. If you aren't testing with OPKs twice a day, some women may miss their surge. Some women can only surge for 10 hours, and you could miss it if you only test once a day. Sometimes, you may skip ovulation symptoms as well. Good luck.