Anyone?

Cindy • I am 23, Married for 3 years, and a mother to a beautiful 2 year old little girl. TTC #2 :)
Has anyone ever had a blood pregnancy test be wrong? I'm just wondering because I haven't had a period at all for January. Was supposed to have it the 14th. My doctor has done 2 urine test and I had a sonogram which showed what might have been a gestational sac so he ordered a blood pregnancy test and it came back negative. If I'm not pregnant I don't know why I haven't had a period yet!! Very confusing!!! 😕