Confused on what I should do(girl problems, sorta)?

Ive met this girl at school. and we're getting to know each other now. we have been talking for about a month. and just recently, this Sunday, she came over my house(first time hanging out), and we played cards, watched movies, n stuff. shes really ticklish, so i tickled her :p. and i put my arm around her when we were watching movies, and she was fine with it. she was over from 4pm-10pmwe were alone for about 3 hours, then my dad came home. and she was fine. at 10, she left, and i got a goodbye hug. we still talk normally, and now shes coming over again next Sunday. probably watching movies again. I dunno if she likes me, or we are just friends. i like her, but i do not know if i should ask her out or not. i am 15 she is 15. we are both not popular, not really high in the school hierarchy. both kinda just normal people. neither have a lot of dating experience. i dont know if its too early, if it will ruin my chances, or what. so, what should i do wonderful people of yahoo answer? ;D