What does five days before mean?

Dear all,

This test kit can be used up to 4 days before your period is due.

2love

The test cannot detect pregnancy immediately after conception. This is telling you that the earliest it can detect pregnancy is 4 days before the next period is due. It can also be used at any time after this. If the period starts, there is no need to use it, so in that case it is a 4 day window, but if the period doesn't come then you can still use the test (and of course this is the most likely time you would want to use it).

...
I think it can be used after the day a baby is conceived and up until 4 days before the next period. My wife however says that it can be only used between 4 days before the next period and the next period (so only 4 days)...

2loveIs2remember: The problem is that advertisers have to be very careful these days when they make a claim: this is in order to avoid being sued. In Britain, their language has become infested with all sorts of stock words and phrases, e.g. "This product may completely cure your pain in just 10 minutes." in place of "This product will completely cure your pain in just 10 minutes."

* I've seen much worse examples!

I think I agree with both of the above. It seems that in this case the due date for the period is taken as a point of departure to limit a period that extends to the 4th day before it. That this makes it hard to pinpoint the exact 4 days in which the test can be used is another story. I know for a fact that, while women generally have an idea when their next period is due, only God knows if and when that will happen. I know women who, based on experience, could pinpoint their next period with an accuracy of plus/minus 15 days.

I agree with

Glasguensis's medical input, but with Biffo on "how to parse the sentence" (based on the writing, and without specific knowledge of the test). Therefore: I suggest the package wording is bad/wrong/incorrect/unclear. (Pick one or more.)

For example, if I stated:

Your reservation can be canceled up to 6pm on the night of arrival. Your seat will be held up to one hour before departure.

But I guess you could parse the sentence -- and the use of "up to" -- this way:

Here, "up to" is taken to mean "as many as".

If the product CAN'T be used reliably until a given time, then

a much better/clearer/more correct (pick one) package instruction would be:

What might help here is to know where the text came from. That is, not "on a pregnancy test kit", but on which pregnancy test kit, and if this is, for example, a statement on a kit made in an English-speaking nation, or a translation into English on a kit made in, for example, China.

As a statement in English the meaning is clear This test kit can be used up to 4 days before your period is due. This kit cannot be used in the last 4 days before the period is due. That is amazing, as it indicates that it can be used any time after the preceding period, and so can predict pregnancy before intercourse takes place!

That suggests that it is a translation into English. Alternatively it was written by a native speaker who doesn't understand the potential confusion inherent in "up to". It should be, as dharasty wrote This test kit can be used {as early as} (or {from}) 4 days before your period is due.

PS

I agree with Glasguensis's medical input

Somebody who is trying to become pregnant may well do.

You don't really need 8 years of medical training to understand how pregnancy tests work

Hi all, Thank you for your thoughts and explanation. I really appreciate them.

This kit was made in China, manufactured by a Switzerland company and is being sold in Sydney. On the packaging, it says Test Early!!! Well, if it didn't have the phrase, I wouldn't have bought it.

2love

2love, fertilisation occurs about 2 weeks before the period is due. Implantation in the womb occurs about 10 days later. Implantation results in the hormonal changes which are detected by pregnancy tests. Some simple arithmetic gives you the earliest possible time that a test can detect pregnancy - about 4 days before the period is due. Since the 2 weeks and the 10 days are both 'about', 4 days before the period is optimistic for a reliable result. Testing less than 14 days after the suspected successful intercourse is definitely a case of "Test Early!!!", whatever language it is written in. Testing any earlier would require time travel.