pregnant no due date

Caley
So lmp was 2nd feb found out I was pregnant a week ago with a digital test that said I was 1-2 weeks that would make me 4-5 weeks today! My last lmp would make me 13 weeks but the doctor says I'm between 6-8 weeks! 
Hope I get a scan soon so I actually know my due date 
Been having nausea for a good 4 weeks now but had ovulation type cm on the 18th April! 
At moment just saying around new year