Thank you for the response! So last night the line was visibly darker then the control line but when I looked at it this morning it was a dark test line but a little lighter then the control line does that mean it was a negative opk?
OPK's detect an LH surge which occurs just before ovulation, therefore when you get a positive OPK ovulation usually happens in the next 24-36 hours, then the egg has approx 24 hrs to become fertilised.
Good Luck :)