Hmm, interesting.
Have your periods always been regular in the past? If so, then something is up if you haven't got it in 6 weeks.
With this pregnancy, which was not planned, I had a missed period then the second week of January I was so hungry when I woke up in the morning. The same way I was with my prior pregnancy years ago. Generally, I can go all day without eating so when this happened I knew something was up. I bought a Clearblue pregnancy test and that positive showed up very strong and very quickly. I believe I was 7 weeks at that time.
Very puzzling and I do agree, it does not rule out you are pregnant until you do get your period.

