Anyone?

Cindy • I am 23, Married for 3 years, and a mother to a beautiful 2 year old little girl. TTC #2 :)
Anyone ever had a blood pregnancy test be wrong? I'm just wondering because I haven't had a period for January. It was supposed to come on the 14th. My doctor has done 2 urine test and don't a sonogram and seen what looked like it could have been a gestational sac so he ordered a blood test and it came back negative. I'm just wondering if it could have been wrong? Because if not pregnant idk why I haven't had a period this month 😕😄