I doubt Amazon themselves make pregnant. Tests it will be a diff brand. The pregnancy tests should have info inside about they're accuracy also depends on if they abide by any standards. In general though positive means positive. If you're not sure you can always buy a more reliable brand.

Just been to the toilet now there was like a little bit blood one looks like a clot ?

I am pregnant

A faint positive is still positive. I personally would not trust pregnancy tests from the Internet. Id rather buy from home bargains/poundland/supermarkets.

I bought similar ones from EBay as recommended by a friend since she said the GPs in our area use the basic ones too. They only cost a couple of pound for about 30. I'm glad I didn't bother to spend a lot on the fancy branded ones as I tested myself approx. 2-4 times per month for 9 months until I got a positive test. They worked a treat and I would certainly use them again in the future. Save your money for baby items and maternity clothes etc. Good luck.