I think i downloaded illegal porn.?

Ok im not a perv sick man im normal 18 yr old. I seen the title loltia porn so i search it on google and i clicked on a web site and it said you must be 18 to enter so i clicked. i click one of the videos. i was just curios and it downloaded a aplication and i was like omg i didnt mean to download this becuase it didnt give me a option it just downloaded as soon as i clicked a picture. and i deleted it straight away but now im scared if the police see iv downloaded that.. What should i do i feel sick