Oh I could have written that post! I am in exactly the same position and sweet FA thus far - AF is 15 days late now. I have a doctor's appointment on Monday to try and see what's happening. I got the faintest of lines on a HPT a few weeks ago but it has not been repeated. So frustrating. Hope you get signs of something soon.
I saw the doctor today and I am being scheduled for blood tests to check hormone levels, thyroid etc. The doctor didn't really appreciate that I cannot arrange an appointment for testing on days 1-5 of my cycle as I have no clue when that is! So frustrating x