Day 21 Blood test timing help?

[5tarlight]

Hi ladies, hoping someone could advise, am sure this topic will have been raised before but can't find a related post... I had +ve OPK on Friday, with temp dip Sat and rise Sun & Mon, so guess I O'd on Saturday 30th, and 7dpo will fall next weekend.
Am already booked for the test on Monday (in advance, a bit of a guess as am not 100% regular) so can either stick with it (~9dpo) or ask to go for Friday (~6dpo). Can anyone advise which might be better (or tell me it doesn't matter!) My LP is somewhat shorter at about 11-12 days (with quite a bit of spotting beforehand) so wondering if that means earlier is better? Thank you for any suggestions! 🙂

My consultant said seven days before my period was due, which ended up being cd18 for me. Not had the results back yet though so no idea if that was correct. Sorry that probably isn't much help!

I ov CD18 and got my day 21 bloods for progesterone taken on CD25 (7 days after ov as per my gynae)- a Monday at the doctors hth x

Thanks both! This is helpful but difference in your replies is what was confusing to me when the LP isn't 14 days - 7 day pre period is hard to predict but is likely about 5dpo, which I think is too early? But feel like 9dpo too late. So it's whether I risk going early and no progesterone peak yet, or later and it could be on its way down... Gah!
Good luck with the results @79andnotout

Hi @5tarlight - yes I've also seen different instructions out there, but decided to go with what my gynae said. I'm fully expecting to have to repeat this test!

Will post up the results here, but as it's been done through my local hospital, and not my gp surgery, results are taking forever! And the consultants secretary never answers the phone, so I just have to be patient...

Thanks @79andnotout! Ugh, yep this whole ttc malarkey turns out to be a long lesson in patience doesn't it (and I know I'm still relatively early on at Cycle 7 compared to many). Unfortunately this one's out of my hands now since I had mistakenly assumed I could make an appointment for a blood test less than 3 weeks in advance..! 🙃 Sooo will go with my 8/9dpo appt on Monday and will also feedback here how it goes in case it answers the question for someone else in future. (And likewise will probably need a repeat.... )