Malware popup

Hi

I have started to use Edge as my browser instead of IE or Chrome But;

For the first time EVER I've just had a popup saying how I have an infected computer and if I don't call this number or try closing the browser my pc will be locked.

I have Never had anything like this on IE or Chrome and my AV is always upto date and I think Norton blocked it but

why did I get the web page and the talking message in the first place?

I have also got superantispyware and Malwarebytes installed.

Thanks