I don't want to jinx myself but I'm having an interesting end to my cycle.

I had naseua from 8dpo - 10dpo. Then it stopped suddenly - BFN

At 11dpo I started to see some light brown spotting - BFN

12dpo heavy brown spotting with cramps - BFN

Today at 13dpo I have very, very light brown spotting that really only appears when I wipe - BFN

So my question is, why would I be spotting and then stop? I've never had a cycle like this. Usually it's brown spotting and then my period starts.

Any ideas? :)