Will the Google ad change if I buy the product?

So whenever I search for a specific item to purchase, the Google ads specific to that product start showing up in place of random ads.

If I purchase that product by clicking on the ad, will the ads related to that product/service change? Will Google know only if I use Google checkout or they don’t even take that into consideration?

I was searching for something online a while back, but I bought it offline. And had to keep looking at the same ads.