21 day progesterone????

My cycle is 30 days(give or take), does this mean that I should actually have the blood test on cd 21 or cd 23? Also, do you know what they test for?

Thanks Kazzle

Just phoned the dr and he confirmed 21 days. Does anybody know why 21 days rather than 7 days past ov? It just seems a bit strange to me.

BTW - I spoke to the nurse who asked the dr so did not have the chance to ask him personally.

hi mummymegs, I have had three of these blood tests, and they do the blood test on cycle day 21 and it is to test for progesterone which is a hormone and the levels of it in our bodies rises after ovulation and it tells them whether you have ovulated prior to cycle day 21, but I don't think it tells them what day you ovulated, just whether it is likely that you have or not . Hopefully that makes sense to you lol

ok...thanks

I hope the results are good news..fingers x

He could still give you day 21 bloods but they wouldnt show a decent level of progesterone if you hadn't ovulated yet, they'd only come up as 'possibly ovulated'.

Your progesterone rises over the 7 DPO and peaks on the 7th day, then slowly drops down again if you aren't preg and once it has dropped low enough AF will arrive.

Your best bet is to get them done at 7 DPO (or a day either side if you can't do it at 7 DPO) to avoid disappointment and for more accurate results to go off.

ETA: Just thought give you an example, last cycle I ovulated on day 18, I had a blood test on day 20 cos I couldn't make it on day 21, it came back as a progesterone level of 9 (so possibly ovulated), I had another blood test done day 25 (7 DPO) and the results came back as 69 (That was on 150mgs of Clomid)

Good luck

Edited by wishin41

I got a level of 3 which sounds very low to me. Anybody got any information about this and what my level should be?

Well if you got yours done on day 21, you would have only been 2 DPO so maybe it was too soon? I'm getting mine done today even though I'm CD26, because I ovulate a bit later too.

I agree that CD21 bloods are supposed to be done a week after ovulation and are only called that because you are "supposed" to ovulate on CD14.

hi mummymegs, funnily enough I thought I had posted a similiar topic a while ago, and I just bumped it up for you, it just might help in understanding the levels a bit better. I know I found them quite confusing to begin with lol

On the 21 day progesterone front, I have to re-do the test and do a cd3 day test. This time the 21 day test must be done, wait for it, 7 days after ov. The dr has also asked me to temp from now on. He reckons it is the best method.

Mummymegs, I think I mentioned this before.

My 21's came back is 0.5 and we conceived. Its all about timing and not everyone fits into the mould.

The temping will help you see when you should be testing your prog.