Most Helpful Guy
There is a good chance because, if that person were not attracted to you and you begin sending off signals that you a highly attracted to them, they will normally change their tone and behave in a way to create more distance and shatter your illusion of enchantment.
Most Helpful Girl
No. You being attracted to them doesn't mean they'll be attracted to you, no matter how strong the attraction is, unless they send the signs of also being attracted.