See below for a call out from the team at Clearblue 
They say "At Clearblue we put women right at the heart of everything we do – from education and technological development through to design, research, clinical studies, field trials and testing. Our mission is to transform the way women manage their reproductive health.
We believe it is important that women have access to accurate tests with results that can be trusted. Therefore we test our products with a wide variety of urine samples so we can make the best possible products.
We are looking for women aged 18 to 45 who want to become pregnant and are willing to use an ovulation prediction product.
We would need you to use a Clearblue ovulation test kit for 1 month, collect a daily urine sample and complete daily diaries. You would then need to send your samples and paperwork back to us by free-post. All study materials and full instructions will be provided. Participation in the study will take approximately 10 minutes of your time each day.
You will be given complimentary product at the end of the study (in addition to the product you have used during the study) as a thank you to compensate you for your time.
If you're able and willing to take part please follow the link to register your details: uk.clearblue.com/survey (Please mention “Mumsnet”).
Typically, more than 5,000 women contribute to the development of each product and we quality check around 30,000 tests before a new product is launched. Altogether more than 120,000 women from 10 countries have participated in Clearblue clinical research to date and we continue to increase these numbers every single day. Based at the Clearblue innovation centre in Bedford, UK we run lots of clinical trials - in-house, by post (like this one), and at study sites in the UK and abroad. For over a quarter of a century we have helped millions of women across the globe by delivering accurate & clear answers at life-changing moments.
All Clearblue clinical research studies are approved by an independent ethics committee and follow special international study regulations. Clearblue process your information in accordance with data protection laws, so you can rest assured that your information will be kept confidential. Your samples and personal information will only ever be used for the purposes that you have agreed to.
Thank you
The Clearblue Innovation Centre Team (Steven Hart, Dr Sarah Johnson, and Pauline Parsons)"
Good luck 
MNHQ