Question on IUI. Achieving 18mm?

I need a clarification on IUI, iam following up with my doctor regularly on my follicular study as iam trying to get pregnant doctor advised me to check if iam getting the proper egg size naturally without any medicine this time so it was an natural cycle without any medicine today isy 18th day where egg size reached to 18x12mm when checked with doctor today she said this is not the proper shape as the length and breadth difference should be only between 2 to 4mm in my case it is 6mm and asked to do one more Follicular study day after still my egg is not ruptured no FF also ET is 13.7 .Dr said if the egg size is not achieved with minimum 4mm difference between width and breadth then to start procedure for IUI with Medicine from 2nd day on next cycle , could someone clarify If length and breadth matters even after follicle achieving 18mm? Have attached my US report below pls verify and help  with your point.