9 days late and still getting negative?

Hi everyone as you can tell from the title, we've been TTC for 7 months and no success as yet. Posted a picture on the faint lines post of what looked like a very faint positive about 2 weeks ago. Now I'm 9 days late but clear blue, the cheap ones from amazon and the first response tests are all coming out negative. My cycles are usually around 36-39 days but I'm now on day 45 and still nothing! I'm otherwise well and I am not especially stressed except that as each day is coming and with nothing happening one way or the other it is getting me more stressed! Has anyone been in this situation?? Any ideas? Help!