Will a girl know if the sperms have entered inside her?

when the sperms enter inside the vagina will the girl come to know that it has entered if yes how can she know......if some of it comes out does that mean it has not entered inside at all..............i am very curious to get pregnant......pls answer me......and if the follicles are small in size are the chances of getting pregnant less or is there no chance at all to get pregnant........