I'd just go for a pack of two supermarket cheapy ones. If your pg it'll show no matter how all singing all dancing the test is. I say a pack of two because if it is positive you can do another - just to be sure . If its neg you have another one to test with in a day or two.
Reliable as in accurate or reliable as in detects early?
Look for the level of HCG they detect if you want Early detection.
The test will have a level of hormone it can detect, e.g 25 mIU/hCG. Theoretically, the lower the limit the sooner it'd pick it up. There are disadvantages with this of course - these very sensitive tests can pick up chemical pregnancies, for example.
I got my first positive with a clear blue digital. The Internet cheapie ones came up positive the day after that. I think the first response early response ones are the most sensitive on the market, but my one was negative when the clear blue was positive...
first response are the best I've done after trying 5! .. I tested with the same wee on a cb that said not pregnant and the first response came up positive very fast despite being faint.. but that doesn't matter anyway
They're much of a muchness. Go with what's local and reasonably priced. The pound shop/home bargains/internet cheapies are often as sensitive as the other ones people have listed on here. 10miu are the most sensitive.
There is no 'best' test. If your period is late, I don't think you need to worry about which test.
Don't be swayed by price either. You're just paying for packaging.
I used morrisons own and got 2 lines almost immediately... Did the second in the pack the next day, again almost instant then did a clear blue digital the day after that... Again all positives and the clear blue estimated I was 3+weeks or in doctors counting 5weeks... Xx