Hiya,
sorry to hear your getting mixed results
ectopic pregnancys still show on tests, although around 5-7 weeks you will feel different, in pain etc, maybe have bleeding, if you have a very early scan and cant detect anything sometimes they say its a possibility its ectopic, but you go back in 10 days if i remember rightly.. then you should be able to see where baby is actually growing..
If your af is due tomorrow, maybe some of the tests are picking up the slightest bit of hcg, and some arnt, which tests have you used so far!
Clearblue can be used from 4 days before af is due, get the digital, that way, it will state it rather than you looking for any line..its expensive but i think you get 3 in those packs, around £18 i think, but you can test every other day,
sorry i cant be much more of help.. hope af stays away and you get your bfp soon