Thanks sepears1,
I know - I've actually been using opks now for 9 months. My question was more as too people opinions IF it was likely that I surged during the night and before the next morning.
And if were more likely I was really at cd13 not cd10
Thanks for answering though :)
On some OPKs, you will have two lines show up but it is not a positive OPK unless the test line is equally dark or darker than the control line.