Ok so I thought I'd drive myself mad and search the chart gallery, I have seen a couple of charts with a dip like mine that ended with a BFP. Implantation dips really can do this crash. A ray of hope, but not counting on it.
Edit, Oh yes I forget to say xshell, sorry bout AF, glad your body is working as it should. I have a CBFM and agree with TripleB. It is fun seeing that peak. Don't forget to bd every other day from when AF disappears though as some ladies find the cbfm jumps from Low to Peak for them.