I can see traffic coming from google ads, even though I don't have any google ads running, how is that possible?

One of your affiliates is likely paying for a Google AdWords campaign using their referral link to drive traffic to your site (and boost their sales). That's the simplest explanation, and therefore probably the most likely cause of the AdSense referrals you're seeing.

I've had affiliates take out ads to boost their sales before; a welcome side effect of running an affiliate program is that other people sometimes pay for advertising for you. As long as the ads they run aren't misleading, it's usually good for business.