FMU with OPKs?

[clementinesandbananas]

Is this a bad idea?

I'm aware using FMU for an OPK could mean that you miss your surge (since it starts during the day) but is there a risk of a false positive (since your urine is so concentrated)? Or is it not possible to get a positive OPK unless you're surging, however concentrated your urine?

I drink lots and struggle not to have dilute urine during the day.

Any ideas?

Thanks but that's not really what I was asking.

I'm aware of needing to have regular sex etc (this will be baby #3) but my question was whether using FMU for an OPK is reliable, or whether it can give false positives. I'm waiting for my cycles to return after stopping BF so am trying to find out whether I'm actually ovulating yet or not.

What opk are you using?
The clear blue suggest fmu :)

Fox hugs, I thought the OPK shows the surge, which suggests ovulation will occur within the next 24-48 hours ish, and I have never heard people saying you can't get preg the day of ovulation?! Surely that is a prime day to get results?

OP. I don't think you can get false positives on the OPk due to fmu but I might be mistaken.

Right, opks show the surge in LH that takes place before ovulation. Research has shown it usually takes place 12-48 hours before ovulation, and on average 32 hours. So usually, if you dtd on the day of the positive you should have caught the right time, taking into account that sperm needs a little while to swim up the tubes (I'm not sure how long and I think they don't really now).

For a few days I used both the clearblue OPK that you use with FMR and a regular OPK. The regular one I used in the morning with FMU as well and then two more times during the day. I used to get a stronger line with the regular OPK in the morning, but not a positive. The rest of the day the lines were not as strong. So you could use the OPK in the morning, if it's negative it will still show you a line, but not as dark as the control line. I presume when you get a positive it will truly be because of the LH surge, but there is a chance that you're not actually peaking yet, but building up to it? Or you may miss the surge if you don't test later on? I drink quite a lot during the day, but I set myself a certain time where I remembered not to drink and not to go to the toilet, so I could test.

If you rather test with FMU it's better getting a clearblue test, even though it's more expensive.

My understanding was that the LH is released during the night so by fmu hadn't had time to be flushed out. So I don't think it would give a false positive.
I've had better results easing off the water for the last half of the afternoon and testing as soon as I get in from work.
Hope that could work for you.

Ok - so I think the plan is to test in the morning with FMU. If it looks like it's building to something, then to stay off the liquid during the afternoon and test again later. From memory of ttc before, my surge isn't tooo short, so I shouldn't miss it waiting 9hrs or so.

Now all I have to do is actually get a surge... I never thought stopping BF would be the thing that messed up my cycles!!

I've become pg using opks. Mine say not to use fmu as we always have a bit of the hormone in us. But it doesn't matter, I use the sensitive ones and test twice a day so I can pinpoint when it's on the rise and not miss the window.

Foxhugs - thanks for that - the first explanation I've had for why OPKs have never worked for me!