I want her tobe pregnant so bad...?

My wife has been having some signs of pregnancy (soreness, cm, no period cramps, NO PERIOD, ect...) she is aroun 2-3 days late on her period, and very little signs that its coming. I guess the biggest sign working in favor of it coming is the fact that she took a pregnancy test today, and it came out negative. I dont get it, what is going on, could it really be that she is pregnant and the tests are wrong. Or could it really be stress is involved. I just dont get how stress can really deter a period for close to 3 days going on four. I dont get what is gonig on, i want nothing more then for her to be pregnant, so i guess this is why im getting so worked up over it. I want an answer know, i dont want to wait and see. I know its either go to the doctor or see if the period comes, but she doesnt want to go to the doctor right now, she says it still is early and wants to wait. I just want to know now. how good of a chance is it that shes pregnant when test says no and she is 2 days late?