No period.. Pregnant?

Hello. I was supposed to get my period on the 21st of November. Well I am now 19 days late. I'm pretty regular, plus or minus a day or two. I have used a "due date calculator" it said I was about 5 weeks and some odd days. Well I've taken two pregnancy test. One in the morning and one during the day on two different days. A week apart. They both came out negative. I have had symptoms of being preggers. Fatigue, moodiness, increased appetite, lower back pain, headaches, dizziness, nausea. I plan on seeing if I get my period for this month and if not then go and get another test. I'm really hoping I'm pregnant, I've had one miscarriage. What should I do?