Ava has not been tested for use with fertility medications such as Clomid, Letrozole/Femara, Metformin, or progesterone supplementation. It's possible that Ava could work normally for women who are taking these medications but we do not have any clinical data on this topic.
Any medications that alter your natural physiology can have an impact on the accuracy of Ava's algorithm, however there is value tracking your individual parameters day-by-day and observing the changes in your body (e.g. the spike in body temperature that indicates you've ovulated). Doing this will not just give you a new level of insight into your cyclical rhythm, but it will also enable you to monitor how well your cycles correspond to Ava's calculations.