So discouraged...please help me try to understand :(

.....(background info: my cycles are normally irregular from 31-47 day cycles, we have been ttc #1 for 6 months, haven't used any birth control for over 5 years).........AF was not supposed to start until 10/25! 10/7 - 10/12 were my fertile days, and I thought I was on track this month, checked my cm and it was egg whites from 10/7 till yesterday which made me believe I was for sure fertile and going to ovulate , we BD on 10/7- 10/11 using pree seed, well today it all changed A F showed up! I am so confused and discouraged.....I was checking CM every day, also used opk twice a day, never got a positive , it did get darker a couple days but never like the control! Just not sure what to do! If opk's, CM check and calendar tracking are all telling me something different, how am I ever supposed to conceive :(.... (have a doc appt Thursday, I know they will tell me haven't been trying long enough to do any medical intervention :( ) please share opinions and what helped you conceive!