You have been trying for 8 months and already had you and your DH checked? Are you over 35?
I was just in the dr for my yearly and she said that I should come in if I'm not pregnant after trying for 6-8 months and I will be 30 in May. I think it just depends on the dr.
OP I would saying charting is your best chance to find that window, I have 35 day cycles and was trying at the wrong time, I thinking I as 28. Once I started charting it all became more clear. I would say that would be your best bet. Good luck and hopefully things start to turn around soon for you and your DH