I Took Utovlan For Two Weeks Whilst On My Honeymoon.

I took utovlan for two weeks whilst on my honeymoon. I have had a period since then and have used an ovulation kit to track when to concieve. The tests and app I have said my fertile days should've started on the 9th August I started testing a couple of days before this and have done once a day since then but I am still getting a negative result. Could this be due to having taken utovlan?