Hi Amy,
If you can ovulate on your own, you won't take any meds, but they will still monitor you to see when you are ovulation so that your uterus environment best matches/replicates the right timing for the embryo to be transferred back. This will mean that your uterine lining and hormones match what they would do if you were getting pregnant naturally, hence giving you the best chance of falling pregnant.

Hope this helps and goodluck!