Not sure if pregnant???

So I went to the ER a couple of nights ago for heart palpitations. Of course when I get there I start feeling better. But they take a urine sample to see if I’m pregnant because I told them I have been TTC. Well the test came back positive for pregnancy. I’m shocked! Only because I took at at home test a few days before and it was negative. I decided to take another at home test today and they are still showing negatives. I am so confused because the hospital tells me I am but my at home test are negatives....help lol.