Why do Clearblue OPKs say it's ok to use first morning urine but other OPKs say not to?

Question

I have just bought a Clearblue digital ovulation predictor kit. It says on the instructions that it can be used anytime, but many women prefer to use it first thing and also this is good because you have to hold your urine for 4 hours before using it.

But I have other OPKs which say NOT to use first morning urine because LH is synthesised overnight and isn't present in first morning urine.

Both tests seem to work in the same way, detecting the LH surge that occurs before ovulation.

So why the different instructions??? Does anyone know?

Answer 1

lets go with the majority here.i m going to use the same clear blue for the first time as well.most of the docters & OPK say to use the first urine of the day so i m going to go ahead with that.even for the pregnancy test they say to test with the first urine of the morning.so just stick with that only.i trust clear blue becz i think its reliable.all the best.

Answer 2

I have always heard to use morning urine because it's not diluted. I would def go with that.

~MLF~

Answer 3

Everyone i know who have used POK's say not to use 1st morning urine the best time is between 10am and 8pm i am not sure what the difference is between them maybe it's the different brands that say morning or anytime.Maybe ring pharmacist and ask them.

Answer 4

This month I used clearblue digital OPK and some test strips. The only way they work for me is if I don't drink till 2pm and take them then.

If I take them in the morning they don't work.

Good luck x