Is this normal

I went to the ER n they told me all of my testing showing that I’m definitely pregnant but the ultrasound wasn’t picking up the baby which means it’s to early to tell n that I should go see my OB in 7to 10 days? I’ve had an ectopic pregnancy before n lost one of my tubes already so I’m very nervous n scared but she said the ultrasound didnt pick up any signs of an ectopic pregnancy.. but I’m cramping a lil but not bleeding. But is this normal and is it normal for an ultrasound to not pick up the baby?!