Help!

Okay so here's the scoop, I have been having some pretty substantial cramping for the last week going on two, and for the past week my nipples have been incredibly sore and sensitive. I have also been experiencing frequent urination, as well as on again off again head aches. I took a pregnancy test...it was negative, and I'm absolutely crushed. I was so sure that I am pregnant. I also tested about a week too early. Does anyone have any advice or positive experiences they can share with me. We haven't been trying for very long, but we are both young, fit, and healthy. I just want to be a mom sooo badly.