Doctor appointment advice

My husband and I have been TTC for 3 months and doing everything by the book, tracking ovulation, keeping a low stress life even with our two year old and 5 month old. We are on a timeframe because I am going back to get another degree in Nursing next January and if it doesn't happen soon, we have to wait a couple years until I am out. At what point do young onto OB about this? Will they make you wait a certain period of time? My periods have not been regular so tracking ovulation has been very difficult. Any advice is appreciated, thank you!!