When should I go to the doctors

Natallia • 24 yrs married 14/1/17, been waiting 2 years and finally have our little boy 💙🥰

I live in England and I found out last Friday that I’m pregnant, going by my last period I’m 4weeks 2days, I’ve read a lot on here but not sure when I should go or when they would actually see me? Do I need to be a certain amount of weeks before they will see me?