u/AutomaticAccess5483

I opened up a tab, I don't really know how it came up but this tab for a virus scanner came up and told me that I might have viruses. I pressed the scan button and needed to press multiple popup scan buttons. I realize now that they was super stupid and I am worried that those were disguised pop ups for downloading something. (also after the scan thing it wanted me to purchase an antivirus so that could be all it did but I heard that these things usually are malicious in multiple ways.) Nothing appeared in my browser download history but I looked it up and appearently some virus' can download themselves even without appearing there. I don't know what to do. Is there anyway I can make sure I don't have one and what do I do if I do?