Accuracy of OPKs

[Sp4rkl3s]

There seems to be a variation of guidelines as to when ovulation occurs after positive OPK. I've read anything from 8 hours to 72 hours. I've also read that the time between positive test and ovulation gets shorter with age. The kit I'm using says 24-36 hours. I appreciate it will be different for everybody, but wondered what is likely if anybody knows or has experience?

[maidentomother]

There is a lot of variation, not only from woman to woman but even for just one woman from cycle to cycle. For example, I've always had regular cycles averaging 28-29 days and my hormone levels are smack dab in the middle of normal/healthy range. My LH surges are often short (just a day) though they can last 2 days and rarely 3. About 60% of the time I O 36 hours after my first positive OPK, but 30% of the time I O 12 hours after my first positive, and then 10% or so of the time I O 60 hours after my first OPK. And there is no way for me to know in advance when I will likely O. I only know when I O in relation to OPKs bc of very methodical temping & charting for over 10 years plus several cycles with ultrasound monitoring.

Obviously I can't tell you when you likely O, though I believe 24 hours after first positive is the average overall, it's not something you can bet on. And while the stated range many places is 12-48 hours, it can be longer than that. Some women regularly O 3-4, even 5 days on occasion, after their first positive. The best way to determine O, outside of seeing a dr, is to temp vaginally and do so carefully. Temping is by no means perfecf and it doesn't work for everyone, but most women are able to see clear temp shifts from careful vaginal temping. If you have enough experience and/or your body is regular enough, you should be able to guess when you Oed as soon as your temp spikes, the morning after O.

Edited to add: atomic actually wrote & sells an ebok all about your surge, OPKs, and how to interpret them. I haven't read it myself but she definitely knows her stuff and I believe it's the only thorough source of its kind. As I said, it's actually quite a bit more complicated than standard literature accompanying OPKs suggests.

[atomic sagebrush]

To paraphrase Churchill - OPK suck, but they're what we have!

They're very imprecise things and thus, no one can really give straight answers. THe average is 24-36 hours after first positive but it can supposedly be anywhere from 8-48 hours, and I've heard of some gals who do regularly go more like 3 days. I personally believe that most of the time anyone who gets a pos and then ovulates very soon after, proably is a bit of user error involved (testing wrong time of day, not regularly, or diluted urine)

The good news is, we actually don't NEED them to be super precise. The goal of using OPK is just to be in with one attempt and to be sure that attempt comes BEFORE ovulation and not afterwards. It really doesn't matter if you O 8 hours later or 18 or 28, if you have your attempt the night of that first pos OPK, then you're in with a nicely timed attempt for odds of conception.

Just don't wait and wait around for your tests to get darker before having attempt. You count from first positive, not darkest. Even if they get darker later.

[The Anchor]

^^^ Here here! Wanted to add that my RE told me (I didn't ask for any evidence to back it up, but it kinda makes sense) that the older you are the "harder" your body has to try and O. Sometimes the LH surge is there, but weak, so it takes a couple of days to work up to the O. It is different for every woman from cycle to cycle. I had 6 monitored cycles in a row, 5 of them I O'd at around 48 hours, and 1 of them at 12! I also think it has a lot to do with when and how you do your OPKs. GL!

[Sp4rkl3s]

Wow, what great knowledge, thankyou so much.
It's all very interesting and I love to learn about how our bodies work and hear of others experiences.

[Grace]

So what happens after ovulation has occured? Do you expect to get negative opk or do you get a faint line?

[True Blue]

I think it's best just to stop testing after you get your first positive. Otherwise it gets very confusing

[atomic sagebrush]

So what happens after ovulation has occured? Do you expect to get negative opk or do you get a faint line?

It is different for every person, in every month. Sometimes you have a surge for only a short time then it goes negative even tho you have not ovulated yet. Other times it takes your body longer to clear the hormone aand you can have a pos for days after ovulation. Don't worry about how long hte tests stay pos for, just use the first pos as a heads up that O is nigh.

[maidentomother]

So what happens after ovulation has occured? Do you expect to get negative opk or do you get a faint line?

Usually, for most women with normal cycles, OPKs will fade out to negative 1-2 days after O if not earlier. I personally always confirm the fadeout as in cases of 3+ days of positive OPKs in a row, O often doesn't happen until the last day of positive OPK.

[atomic sagebrush]

Swaying can alter the patterns though so I think it best for people to not put stock into how their OPK go neg.