How many weeks pregnant?

Hi all. Got my first ever positive yesterday. Still a little numb and unable to actually believe I’m pregnant! Now I know your pregnancy is counted from your last period so I’m classed as 5 weeks, but my conception date was 3 weeks ago. So when I’m reading things online and getting my head round everything- should I be looking at 3 weeks or 5 weeks?

I’m also still having period cramps daily- on and off- is this still normal?

Super excited and equally as anxious mom to be!