Missed period with bfn

Have you ever missed your period and still got a bfn? I've been pretty regular and now I'm 8 days late. I of course took and hpt and they are all negative. 😥. Then I took a opk and it was very dark on the test line. Do you think I could still be pregnant or maybe I just missed my period and I am ovulating twice the month? Also comment if you ever had to wait a long time after your missed period  for a bfp. I'm just wondering if I should stop hoping this month. I'm just figuring that, if I was pregnant, I would be showing up on a test by now, right?? Thanks for your input.