My experience with faint lines is not positive I'm afraid. I've had 4 pregnancies but only 1 that's gone past 5 weeks. With the early losses my HPTs were really faint and did not get darker as the days went on. With one of the pregnancies I got a negative result in the middle of 4 positive ones (two + one - two +) - I then tested positive with a BT but the HCG had halved two days later so we knew what to expect.

With this pregnancy I had a faint positiveHPT 7 days after O so at about 20dpo and by the next day it was a very clear positive.

I have seen lots of ladies with faint + HPTs that have gone on to have healthy pregnancies, this is just my experience with them.

I'd suggest you head off to your GP for a BT and ask what your HCG level is when you get your results so you can compare it to the next one if it is positive (and I hope it is).

Best of luck.