Stopping TTC after October

This is my second cycle TTC and I know it can take the average couple almost a year. I'm giving myself 8 months. We wanted to be due in April so that I could take off work through the summer. I realized that was unrealistic and we just started trying in March. I just don't think I'm willing to take off the first month of school and have a sub set up the atmosphere and routines in the class especially since I teach kindergarten and that's huge for us. Am I being unrealistic in my hopes that it will happen in under 9 months?