Is it false positive?

Hi there mommies and future moms, Im a newbie here, just wanted to know if others have also experienced this, my last menstrual period was January 30, had a blood serum pregnancy test last Feb. 22 and got a positive (weak reaction) result. Had it done again on Feb 25 and had the same results. I decided to visit my OB and asked me to take a urine pregnancy test and it also turned out positive but the second line is faint, the same with the 2 blood serum PTs I had. Today, i tried the urine PT and the result is negative. My next OB appointment is on March 4. Any thoughts on this? Thanks in advance.