6 days late... Negative hpt this morning

Amanda
I've ALWAYS had a 31 day cycle and am now on CD37! I usually always have very sore BBs a week before AF, but nothing. The only things I'm feeling are slight cramps throughout the day and constipation.
We have been TTC for a year now and over the last couple of months we have stopped trying (AKA- I stopped obsessing). So I haven't been temping, which now I wish I have been doing. 
Is it possible to just skip a period?!? I haven't ever experienced this. 
Has anyone else experienced this before?