I am a guy and if i masturbated, would it cause any harm to my fertility?

No: As long as your sperm count is normal, then ejaculation by masturbation or intercourse will only decrease sperm counts for about 24 - 48 hours. Sperm counts replenish quickly for most men.

Possibly: Masturbation like frequent heterosexual sex (if done too frequently while attempting to get pregnant) could cause issues with fertility if one is attempting to cause pregnancy. It is simply an issue of sperm count and quality of sperm. Essentially you could deplete the count and hinder fertility. Otherwise, masturbation is not going to be a cause of infertility.

No: Masturbation does not affect fertility. Howver, if ones masturbates frequently, it will lower the volume of your ejaculate and indirectly this may lower your chances of conception. Therefore, if you are actively trying to have a child try not to masturbate frequently to build up the volume of your ejaculate at the time of her ovulation.

No problem: Masturbation does not decrease your fertility. Men constantly make sperm, essentially throughout their life. If a man has a very low sperm count or otherwise poor semen quality then frequent masturbation of ejaculation can make their fertility worse. If the semen is normal then it would be very difficult to make a problem. I hope this is reassuring to you. Best wishes.