Why is a faint OPK line a negative?

[Allthebees]

I'm using the green internet cheapies and test at around 2pm each day.

Yesterday and day before no test line appeared at all. Today the line is faint.

Is it considered negative because its detecting a little bit of the LH hormone but not enough to indicate OV is in its way?

Should I be testing again later? Would I be right in hoping I'd get a darker line in the next couple of days??

How often should we dtd from now?

DD was a happy surprise so didn't have any of this with her!

Opks test for luteinizing hormone, which is present in lower amounts all the time. Just before ovulation there is a massive surge, that is why you need a dark line. I would ensure you are having sex three times a week and then make an extra effort when you do get the positive
when i used cheapies i did twice a day from day 12 onwards.