Bullet Firing Every Frame

So I wrote this shooting code so when the player pressed left mouse button a bullet will fire. However, a bullets if being fired every frame even when i didn’t press fire. Help!!

Shooting Code:

using UnityEngine;
using System.Collections;

public class PlayerShooting : MonoBehaviour
{

GameObject prefab;


// Use this for initialization
void Start()
{
    prefab = Resources.Load("Bullet") as GameObject;
    

}

void FixedUpdate()
{
    if (Input.GetMouseButtonDown(0)) ;
    {
        GameObject Bullet = Instantiate(prefab) as GameObject;
        Bullet.transform.position = transform.position + Camera.main.transform.forward * 5;
        Rigidbody rb = Bullet.GetComponent<Rigidbody>();
        rb.velocity = Camera.main.transform.forward * 100;

    }
}

}

   `

if (Input.GetMouseButtonDown(0)) ;
you have a semicolon at the end of your if, effectively ending the if-check.

also, why are you using input within FixedUpdate() instead of Update()?

ty for the answer that actually fixes alot of problems i have always had with unity lol. I used FixedUpdate has a desperate attempt to fix this, I just never changed it back. Ty