When to do the 21 day test?

[greengecko]

Have been ttc for one year without success. GP has asked me to book appointment for 21 day test. Should this test always be carried out on day 21? I've seen some information suggesting that the test should take place 7 days after ovulation, and other information suggesting the test should be 7 days before your period. I've been charting my temperature and doing ovulation tests for the past few months. From that I've worked out that I ovulate around day 17. I have a 28 day cycle. My temperature charts suggest a short luteal phase of around 7 days. Should I test on day 21? Or day 24? Or somewhere in between?

If you have a 28 day cycle and ovulate on day 17, don't you have an 11 day luteal phase?

My understanding is that a 21 day test should take place 7 days after ovulation - so for you that would be day 24.

TBH it won't make a lot of difference if this was done on day 21 or a couple of days afterwards. The day 21 is a standard test done to measure progesterone - they like to see a level of 30 or more.

However, this test is only part of the story - your LH and FSH levels should also be tested too. This is usually done early in the cycle around day 3. If your LH and FSH levels (these levels ideally should be the same) are awry then chances are your progesterone is awry too. Ensure that the earlier test is done also.

LPD is controversial; some say it is a problem, others are not so sure. I would try and have the day 3 test done as well in due course as this will give you a fuller picture of what your hormone levels are like.

As you have been ttc for a year now you should be referred as a matter of course to hospital for more tests on both of you. You need a diagnosis first and foremost and sometimes as well these problems are outside a GPs remit.

i totally sympathise greengecko. Have been ttc for past year and went to doctors for advice. Was only in at the most a minute and she babbled about a day 21 blood test (although i had taken all my ovulation/period info with me) and that was it. Felt like i had wasted my time as GP was not supportive and i had already waited a month to see her!
Think am just going to have to do this before they can do more
good luck!

My GP didn't describe it was the 21 day test at first, she said '7 days before your period is due' I have a cycle 28 - 31 days so I'm going on CD21.

I was also given the papers for a CD2 test as Attilla said.

The GP said that these tests have to be done before you can be referred onwards. I did wonder why, because if they showed problems surely you'd need to be referred on for help with those problems, and if they didn't - surely you'd need to be referred on for more tests to try to identify what may be wrong???

I did wonder if it was just a way of stalling things for a month or so.

It needs to be a 'mid luteal phase'progesterone. The luteal phase is the time after ovulation but before the period. So the bloods need to be done roughly in the middle of this time.

Trouble is, usually you don't know when you ovulate, so you will only be able to guess in retrospect when your period comes.

For most women, they ovulate approx 14 days (give or take a couple of days) before the period - so for a woman with an 'average' cycle of 28 days this will be on day 21. But if your cycle is longer this will be obviously be wrong.

The usual advice is that if you have a regular cycle, take the average length and get the bloods done a week or so before you expct your period, hopefully this will then be confirmed to have been done at the right time when you get your period at the right time. If you are using OPKs then you may well have a better idea of when to do this - half way between the OPK and the expected period is the right time.

It gets more tricky if you don't have regular cycles - you just have to make a guess as to the best time. Sometimes it is necessary to do serial bloods - this is done regularly from 7 days before the shortest ever cycle until 7 days before the longest, but hopefully that won't be needed.

Oh and the reason for doing the tests before you are referred is that otherwise the hospital will want those basic results (bloods and sperm count) before doing much else, if you haven't had them done you will then have to wait to get them done at the clinic - and that will much more prologed and complicated than arranging it via the GP for certain!

Thanks for all the advice - much more helpful than my GP!