Yet another OPK question...sorry I know there are lots but I can't find this one specifically 
I am using Superdrug own brand ovulation predictor sticks for the first time. Usually I use the litmus-strip looking very cheap ones that I buy in bulk from Amazon.
On CD 6, yes SIX, I got two lines the same colour. So DH and I started DTD. Then I got two lines the same colour every day until yesterday (CD12) when I got the test line darker than the control line.
So was my LH surge yesterday, and the rest just a build up? Normally I get no test line until day 10, then two lines, then a darker line on around day 13.
I suppose this means we have to DTD all weekend, which should be a thing of joy but DH is getting a bit, um, jaded
Any advice?