Fertility tests

[Rachjg13]

Me and my husband are currently having tests done as we are struggling to conceive.
The doctor has said to have a blood test on day 2-5 and day 21 of cycle.
What is classed as day one? I have had spotting today the blood is either brown or red is this day one or not. The doctor said he first sign of blood is day one but read online it’s when you have full flow. I am concerned as need day 21 to accurate so want to get day one correct. Thanks

Day 1 is the first day of your period. I guess you have to determine if it’s only spotting or your period that has come. If your period is due, even if it’s light I would say that’s Day 1. Unless you get this kind of spotting at other stages in your cycle? If not it must be your period. I think your doctor should be in a best position to give you correct advice rather than online

The day 21 test is for ovulation and should technically be taken 7 days after you've ovulated. So the day 21 suggestion is based on an average 28 day cycle where a woman ovulates on CD14. Do you usually track your cycles and ovulation? Might be worth mentioning to your doctor if you think you'd usually ovulate on a different day.
CD1 is usually counted as the first day of full flow but generally it doesn't matter if you count from spotting as long as you're consistent each month.