Am I pregnant


So yesterday I took a random pregnancy test. It was clear blue digital and it said I was pregnant. Hubby and I was overjoyed. I'm in thr Army so I went to the hospital to do another test this morning so I could get a pregnancy profile. That test came back negative. Of course we were heart broken. I came home and took another type of pregnancy test. This one was the plus/minus but still clear blue. That also said I was pregnant. The doctor have me scheduled to do a blood test but I'm nervous they will say my test is negative again. What could be causing these positive pregnancy test at home?