Please or to access all these features

Add post

Watch this thread

Save thread

Start a new thread

Flip thread

Hide thread

My feed

Active Unanswered threads

Getting started FAQ's

Unanswered threads Acronyms Talk guidelines

Hide shortcut buttons

Talk

Conception

When's the best time to get pregnant? Use our interactive ovulation calculator to work out when you're most fertile and most likely to conceive.

Flip

Original poster

When exactly is CD1

9 replies

CrazyCatLady75340 · 31/08/2021 02:17

..if your period starts at 10pm?

May be a stupid question, but do you count the day it starts, or the first full day considering it's late at night and so close to being midnight?

If I'm in bed early I wouldn't notice it had started until the following day, but if I'm up then I would at that would give me two different answers.

Anyone know what the medical take on this is?

OP posts:

Driftingblue · 31/08/2021 02:25

I was under the care Of a specialist reproductive endocrinologist.
Cd1 is when you have real flow before noon.

So 10pm means cd1 is the next day.

Original poster

CrazyCatLady75340 · 31/08/2021 02:49

That's really helpful, thank you!

OP posts:

thislittlebird · 31/08/2021 11:00

Yeah this is useful info. We’re venturing into the world of ivf and I thought I’d read that cd1 was full flow during the course of my research. But I spent all my life counting the day before as day one, which was almost always just some spotting. Have now adjusted my cycle tracking accordingly!

Kay00 · 31/08/2021 11:19

I can second what @Driftingblue has said. My consultant has said it is the first full day of red bleeding, so if I start in the evening then day one will be the next day.

Original poster

CrazyCatLady75340 · 31/08/2021 14:21

Funny isn't it. I've had periods for the last 20+ years, but yet the most basic question just completely throws me 😂 I wouldn't be surprised if a lot of people got this wrong.. I've been using an app to track everything for about a year and had no clue. Thanks both!

OP posts:

Bundaberg84 · 31/08/2021 14:35

@CrazyCatLady75340 ha - I didn't know that either, but now it makes sense why my cb monitor wants to know at what time my AF started. I was very confused as to why that would matter.

IsabelHerna · 31/08/2021 21:10

Wow, great question! Thanks for the info!

Original poster

CrazyCatLady75340 · 31/08/2021 21:11

I don't feel so silly asking now 😂

OP posts:

French66 · 31/08/2021 21:33

I think it depends on the person. I've been having 10 day bleeds and marking day 6 as cycle day 1, due to red blood, cramping and flow. The first 5 days are just spotting. However, all my scans have shown that cycle day 1 is actually the first day of spotting and sometimes I have already ovulated before the bleeding stops. My consultant did say that the first sign of blood is cd1. I dont think it matters too much for you, as it's only a matter of hours rather than multiple days.

Flip