confused!!! HELP!!!

Jasmine
I got my first BFP Sunday it was very faint so I texted again the tuesday just to make sure it wasn't a bad test. I previously had an eptopic last April and my cycle has been very on time. I went to the emergency room to make sure baby was in the right place. They did urine and u/s . The results came back that I wasn't pregnant but I'm still testing positive I took another test this morning I used the test from my job I work at a hospital. So I'm lost was it too early for them to tell?