My last period was the 28th August and I have done several pregnancy tests all say negative except one which was a really faint line, could I be pregnant

If pregnancy test isn't working always go with a blood test.

If you followed the directions carefully, especially regarding when to read the results, and got the faint positive, you are likely pregnant. Very rarely will there be an inaccurate positive.

As was said, you will need to confirm one way or the other.

Are you using the early first morning urine and following the instructions properly. But a faint line is most likely yes.

Go to a women's clinic, or the health department or your doctor for a blood test to be sure if you need to