Confused??

Hey! So husband and I have been ttc for 9 months now and still no luck. AF is 13 days late at this point but I keep getting a BFN when I test with first morning pee. This happened one other time and it's because I was stressed. I don't feel as stressed this time but I always have a regular 28 day cycle. Anyone have this happen and end up pregnant? I can't stand another month of waiting... :'(