Well officially going mad!
I did another first response this morning and thought I saw something a test filling up that was about 8/10mins ago and I still see something, gonna see if it randomly gets darker.
Stupid thing is with my last 2 pregnancies I found the £1 shop tests worked better than first response and I had strong lines when first response was pretty much negative, so think I shall be going £1 shop today! And getting some good old cheapies xxx