Heather is right, they also use blood tests to check hormone levels during this time, to make sure you are on track, and also to make sure you Ovulated. good luck to you:)
Do you mean a monitored cycle, where they check your follicle's growth and make sure you ovulate? If so, then it is done with internal ultrasounds throughout the cycle. I'm sure this can vary a little from doctor to doctor...but you will usually have one around CD (cycle day) 3, to make sure you have a good number of antral follicles (or "resting follicles"), then another one around CD12 to make sure one has become the dominant follicle and grown. If it's not mature yet, your doctor might set up another sono a few days later. Then, once the follicle has reached maturity, you should ovulate (either on your own or by using a trigger shot), and finally, you'll come back a few days later to make sure the follicle ruptured. Best of luck!