A little Big problem...

I'm pretty good with computers but I faced a virus problem last night. My laptop diagnosis is saying that there are no viruses or issues with my computer but I keep getting a pop up that is saying threat detected, warning, warning, warning...and they ask me for a credit card to update protection on my laptop. I think its a scam and I refuse to give out my information. I've been running scans but they are stopping before they get to finish. Anyone know what the problem might be? I'd appreciate all the help!!