Frequent male masturbation isn't likely to have much effect on your fertility.
Some data shows that optimum semen quality occurs after two to three days of no ejaculation. But other research suggests that men who have normal sperm quality maintain normal sperm motility and concentrations even with daily ejaculation.
Ultimately, having sexual intercourse with ejaculation several times a week will maximize your chances of getting your partner pregnant, whether you masturbate or not.