Negative then positive?

Andrianna
Ladies I need your help! I am a week and two days late for my period. I've been experiencing dull cramps and fuller breasts but that's it. My cycles are usually 29 days and today makes 40. I've never ever been this late before. I took a test when I was 5 days late and got a bfn. So my question is, has anyone taken a pregnancy test after your period was late and got a negative, then later got a positive result? Or, has anyone ever experienced PMS but no period?