hmm. Sounds tricky. I'm really not seeing much on any of your tests. If you don't know how many DPO, do you know when you could have possibly conceived (i.e. had sex unprotected)? If you know that, you should get some sort of a positive test sometime within 14 days after that if you are pregnant... Not every woman gets a line right away after conceiving, sometimes, for some strange reason, it takes a really long time for the line to show up, so this could be the case. If you DTD (unprotected) a while ago, and are still not getting positives, its likely you're just having a long cycle. Good luck!