If my website uses HTTPS for login then can I server advertising pages?

I have a web site that is used for online surveys. Users will log in, take a survey and at the same time I would like to present them with pay per click advertising while they are viewing the pages.

I would like the users to see the HTTPS secure connection on login so I assume I need a certificate installed.

I did read somewhere that if a page is using HTTPS then it would not be possible to display Google Advertising there.

Can someone please give me some advice on this. I am very new to this and would appreciate any help.