Hcg levels

Lucy

Been to the hospital because of back pain, they said I have uti and on antibiotics. My frist day of my last period was 5th July meaning I am 6 weeks pregnant date of ovulation was 20th July meaning 4 weeks, they did a scan and came up looking like I was 4 weeks not 6, I just don't get why they add 2weeks on?

My hcg level were 2000

They said I might be miscarriage/ ectopic

I've gotta go back on Friday to see if they double