When to tell boss

Megan

Hey everyone so I am officially pregnant (should be 5 weeks) - my question is when should I tell my boss ? It’s been 7 years since I was last pregnant and then I wasn’t working so I am wondering if I should tell her immediately Incase of complications early on or just severe sickness ? No symptoms yet other than nagging headache and not wanting to eat but nothing to extreme ! Thanks for any input