Thanks everyone! I'm a bit in shock but I've bought some more frer so I can test again tomorrow and see if the line is stronger. If it's a chemical then I've got a bottle of prosecco in the fridge to commiserate.
Physics, wow, triphasic is really positive, that's the reason I was temping on the first place, so I could see that but I gave up temping two cycles ago.
Jem I've got my fingers crossed for you for a double BFP. I've got cramps and feeling a bit nauseated but I don't know if that's just in my head. I'm going out for afternoon tea, I think I'll be designated driver as I want to be about to turn down a glass of bubbles.