What is going on..

We want to have a baby so bad.. this decision just stumbled upon us on Christmas Day. We had unprotected sex Dec. 25th and weren’t careful for the first time in almost five years. I was due for my period in 7 days but since the date has kept pushing back. It’s going on four days that it’s pushed back another day and I’ve been having cramps and heart burn, hiccups, and I’m always tired. I took a test around noon today and it was negative.. but still no period. Could I be pregnant with a negative test?