Get an ovulation predictor kit at a drugstore. Clearblue has a great one, but I've also had luck with the regular CVS brand.
No website can accurately tell you when you're ovulating.
If you get a positive response with the kit, it means that you will ovulate in the next 24-48 hours.
When I got a positive response from my kit, we had intercourse for the next two days. I'm 14 weeks pregnant now!