My wife and I are wondering if she is pregnant. This is our first try. If she is, we estimate that conception would have been four weeks ago (last normal menstrual period six weeks ago). We've been seeing lots of little signs that make us feel she's pregant, but no tests saying she is.

We've also heard on the internet from people who's urine and blood tests didn't turn positive till over four months pregnant. The ovulation tests have not indicated ovulation is happening, and she did have a lighter than normal period (half or less of normal)(we've heard from women who had monthly bleeding during pregnancy so we're thinking her bleeding may not mean she's not pregnant). She's never missed a period and they've ALWAYS been 26 or 27 days apart. Having one with half or less of the normal flow has never happened before.

Indications that she's not pregnant:
Negative urine tests (HCG)
Negative blood test
Period two weeks ago (but lighter and shorter than normal)

Indications that she's pregnant:
Increased appetite and desire for more variety.
Bulging a little below the beltline (pants tight that were never tight before).
Motion sickness in situations where she normally isn't.
Some morning nausea.
Much stronger food likes and dislikes (really wants some foods, can't stand others...)
An intuitive sense that she's pregnant ("I feel like I'm pregnant...").
Sleeping longer and more deeply at night, napping more often during the day. When I move around in bed, she doesn't wake or stir like she normally does.
Ovulation test (LH urine) does not indicate ovulation.
Decreased interest in sexual activities.
Cervical mucus for several days after the lighter "period" (this cervical mucus is unusual for her).


Other information about my wife:
Age: 37
Diet: Vegan (lots of fruits, vegetables, nuts, beans, grains...), much of it raw. No eggs, dairy, Mono-Sodium-Glutamat (Natrium Glutamat) (I'm very sensitive to it...), hydrogenated oils. No wheat (gluten of any kind, doctors orders). Lots of fresh juice (carrot, grapefruit, orange, a little Celery and spinach)
Exercise: walking 30-45 minutes a day

With all these negative tests and conflicting symptoms, what are the chances she could be pregnant?

Has anyone found that drinking lots of water, fresh fruit and vegetable juices, and eating lots of fruits and veges dilutes the concentration of HCG in the urine and blood?