I am 13dpiui. I took a HPT yesterday and one this morning and both were BFN. So now I'm obsessing. I keep doing google searches to see if anyone else in the world has gotten a BFP later than 13dpiui. I've also been looking up late implantation. The internet is great because it's got so much information. But it's also evil because rather than doing the boat load of work on my desk I'm looking up late implantation, etc. I need to step away from the internet and stop obsessing. Whatever will be will be.