Hi Susan,
Again welcome to BB.
It sounds like you are pregnant. Apart from the late period, tender nipples and nausea are classic symptoms.
On most of the tests I used they said that faint lines are usually postive but your hormones are still low. Perhaps you should try one of the early pregancy tests?
I used about 8 tests in all. I kept trying and they kept on coming up negative, one was very faint though but I know I was definately pregnant!! And as you can see I am! I did one of a saturday night it was negative and on the sunday morning it was very very postive.. it was at this stage I gave up, went to the Dr and had a blood test!