Should i be worry about this trojan?

about 30 mins ago i was on the internet and a window popped up and said i have a severe trojan on my computer that was getting my bank account details and my passwords and so on, so i clicked on it and it took me to a website that was selling virus protection so i clickeed off it and then another window popped up... show more about 30 mins ago i was on the internet and a window popped up and said i have a severe trojan on my computer that was getting my bank account details and my passwords and so on, so i clicked on it and it took me to a website that was selling virus protection so i clickeed off it and then another window popped up and said windows would keep me updated or something like that anyway i ran a virus scan on my computer and it didnt detect anything. the funny this is yesterday i just signed up for paypal to you for ebay and i noticed that when i went to type my password it was acting funny and clicking off it and i would have to click back on to it to type it in. but i was also thinking maybe it was just a scam to get me to buy the virus protection product and now im confused and really worried please help?
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