OPK's

**Bubbles** · November 13th, 2007, 08:18 AM

This month I started using OPK's for the first time. I did the test at 5.30 every day because I didn't want to have to do it at work. My cycles are usually 30 to 33 days since my miscarriage at the start of the year (which is more regular than before) however I did not get a positive on the OPK's around the time I thought I would be ovulating. My boobs usually get a bit sore after I have ovulated which they did start doing a couple of weeks ago however last week they were really swollen and sore more than usual. They are still sore and a little bit swollen and my nipples also hurt when I slightly squeeze them. I didn't use the OPK's for about three days and now I have finally started to see some lines. Friday and Saturday they were not darker than the control line however yesterday it was as dark. I am surely not ovulating now as i am on cycle day 33.

Do you think there is a chance that I am pregnant and the OPK is picking this up? I am trying not to get my hopes up. I have also been slightly a bit more tired the last week too (falling asleep on the couch which I don't normally do).

Any advice anyone. I am going to buy a HPT today but I am not going to test until tomorrow morning.

**on tra_k** · November 13th, 2007, 10:19 PM

Good luck with your test tomorrow. I don't have too much advice to offer other than you can still miss the LH surge with OPK testing. Temping and other fertility charting is the best way to be certain about when you O'ed, but of course that only tells you in hind-sight. Everything crossed for you.

Monkeysmum · November 13th, 2007, 10:42 PM

Hi,

There is web site called peeonastick that has a good write up on using opks as hpt. It is possible to pick up HCG and LH on an OPK. Although it is not rec to use OPK as HPT, but have a read and see how you go. Goodluck

Chalalan · November 13th, 2007, 10:43 PM

Found this on the web:

OPK's as HPT's:using an ovulation test to confirm pregnancy

Overall-- yes, it can be done. Ovulation predictor tests (known as OPK's because they are normally sold in a set of tests known as a "kit," thus the K) will show a positive result when a woman is pregnant, as well as when she's ovulating.

Specifically-- while it works most of the time, there are good reasons to avoid using an OPK as an HPT for diagnostic purposes. If you want to pee on any stick that will stand still after you know you're pregnant, just for fun, have at it. But I would not recommend using an OPK in place of an HPT overall.

Reasoning-- OPK's detect LH (luteinizing hormone) which is the hormone associated with ovulation. Pregnancy tests detect hCG, the hormone associated with pregnancy. LH and hCG are, at a molecular level, nearly identical. hCG has a beta subunit, meaning it has an extra little "doodad." To use a stupid but easy to understand example, LH and hCG are identical twins, except that hCG wears a funny hat.

An OPK tests only for the part of the molecule that LH and hCG have in common (the "face" or "body" of the identical twins.) Essentially an OPK is loooking for the 'face', so an OPK will turn positive when it detects either of the "identical twins"-- ovulation or pregnancy hormone.

The reverse is not true, however, because an HPT tests for the part of the molecule that is unique to hCG (the "hat.") So an HPT would be positive only when it finds the 'hat'.

Therefore, a pregnancy test will turn positive only in the presence of hCG, whereas an OPK will turn positive in the presence of hCG or LH.

Now, it's important to note that OPK's work differently than HPT's. A pregnancy test will develop 2 lines only if hCG (pregnancy hormone) is detected. Thus, "a line is a line" when determining a positive HPT. OPK's work differently. An OPK has a "control" line and a "test" line, just like an HPT. Unlike an HPT, however, the mere presence of a "test" line does not mean the test is positive. The test line must be as dark as, or darker than, the control line to be a positive result (meaning that a surge was detected, rather than the ordinary amount of LH usually found in your urine every day.)

This means that there is already some ambiguity involved in reading an OPK's results. Sometimes the line is almost as dark as the control line, but perhaps not quite as dark. Sometimes only the edge turns dark, or the top half of the line is darker than the bottom.

Additionally, OPK's are not as sensitive as a lot of HPT's are. This means that, if pregnant, you are likely to get a positive HPT earlier than you would get a positive OPK

Hope that helps. Google pee on a stick for more info.

**Liviam** · November 14th, 2007, 07:05 AM

I have never got a positive with an OPK even the cycle I fall pg with my DD so I think it is a little bit obvious that I did O. With OPK's you can miss the LH surge and they don't work for all women. Whil some women get positives with no problems.
From memory (not 100% sure though) I think they suggest you do the test around 2.30pm, don't drink for 2 hours before to avoid diluted urine and if you get two lines to retest later that evening. Are you using any other methods for watching your cycle/ovulation?
Hopefully you want need to use these again and best of luck with your test this morning.