Problems Help?

i think i have a problem or i dnt know wat im doing wrong i mean i am a good looking lad and have had my fair share of girls not in a rude way but 4 sum reason any time i chat a girl up i wud take the number down and every fing wud be going well then il probably leave it 3 to 4 days before i give her a call the 1st tyme she will pick up den the second but the third and forth they wont and i make them laugh genrally im a bubbly person thats y i cant understand why they dnt pic up it makes me feel insecure about myself and these gals are like 9/10 gals has any onee gt any opnions or advice i can take tyo better my self and i am only 18 goin on 19 and go gals aged 21 and over and mostly lie about my age and they neva find out HELP PLZ