Poundshop pregnancy test vs branded pregnancy test ?

First pregnancy I used an expensive one when I was 5 days late. Second (current) pregnancy I bought 2 for �1 test from poundland and tested the day my period was due - both positive. It could be effected by when you ovulate and conceive which isn't necessarily in the middle of your cycle, so if it's earlier then it would be possible to detect pregnancy earlier than if you conceived later in the month. It's always worth waiting a few days or a week anyway, just in case.