How soon can doctors detect pregnancy?


So my period is supposedly to come on Saturday 5/25 ... I have gone to the hospital about two days after ovulation they didn’t pick up on pregnancy. I ovulated from May 6-12. I went to the hospital May 14 because i had been sick and traveling. I had been sexually active daily during my ovulation cycle. They tested my urine and it came back waiting on my period because my body is giving me pregnancy vibes. Is it likely that the doctors could be wrong ?