The Clearblue digital was the best test I used. After being late for nearly two weeks and using a test from Poundland (which was repeatedly negative) I decided to invest in a digital Clearblue. I just knew I was pregnant. And sure as anything, it showed up as 2-3 weeks.
I am now 14 weeks in and have even seen the baby via ultrasound. It's growing nicely.
I would highly recommend the Clearblue Digital as it's one of the most sensitive tests on the market. My understaning is that you can often get a false negative, but you will not get a false positive as you have to have the pregnancy hormone HGC in your system to test positive. You wouldn't have this hormone unless you were pregnant.
But I tested negative 5 times before getting the positive result. My doctor was useless and told me that as I had tested several times I clearly wasn't pregnant and was probably just missing a period as this happens occassionally. He told me to come back if I hadn't had a period in 3-4 months. And this was despite me being 35 years old!
I was so astounded at his advice that I went and researched reasons for false negatives and found out that generally speaking the cheaper tests need higher levels of the pregnancy hormone before they can identify that you are pregnant. I tested this theory by testing again with a £1 test when I was 6 weeks and sure as anything it came up positive. Whereas the Clearblue Digital was able to tell me three weeks earlier.
Hope this helps.