Cesely, It is impossible to know when you will ovulate after coming off the IUD. Unless you do ovulation tests, you should probably should only start to look for ovulation after your first menstruation. Even then your next few cycles may be very irregular.
Of course sex every second day will guarantee that your "bases are loaded" when you ovulate. Just don't let it become a job. That is the quickest way to make your boyfriend get a headache
Best of luck TTC!