ovulation test - How dark does a faint line have to be before it become a positive?

[estya]

I've have a very faint line before - I had to look closely to see it - so I put that down to an LH surge.
But today I have a less faint line. Its clearly visible but not as dark as the control line.
How dark can I expect from a positive line? Is it only a positive when it is as dark as the control line?

It's only positive when it's as dark as the control line. BUT surges don't last long, and you may be seeing either the beginning or end of one iykwim.

A lot of long-time users on MN advocate using tests twice daily.

I'll try again later, then.
Thanks

I'm sure the instructions on the tests you have will say that they have to be at least as dark as the control line. If you are using cheapie dipstrips, I found mine never went exactly quite as dark, but it was close, and definitely not a faint line at all.

If you have had a faint line I wouldn't bother trying again later. Save it till tomorrow. Your body can produce LH all month long, some people have a very faint second line most of the time.

I tracked my cycle for the first time this month. On CD14 I got a not-quite-as-dark-as-the-control-strip positive, and then a second one a few hours later, slightly darker but still not as dark as the control. This was after a few days of bloating and ovulation pain. I tested the next day and it was gone.

You probably did ovulate, if you were having other symptoms, but you likely caught the tail end of it.

as pps have said, its got to be as dark or darker than the control to be a true +ve. I test twice a day until I see my line getting darker then X3 per day until the line starts to fade. Even so I do sometimes miss the full +ve test, as I have a very short surge. Other symptoms confirm ovulation for me though, ie ewcm, cp and the temp rise afterwards, so even if I dont get a +ve opk I am sure I have ovulated iyswim.