title: Regex Visa + Mastercard with Spaces need Add Amex
body: <p>I have this Regex to validate Visa and Master card with spaces, it works perfect.</p>
  
  <pre><code>^(?:4\d{3}|5[1-5]\d{2}|6011|3[47]\d{2})([- ]?)\d{4}\1\d{4}\1\d{4}$
  </code></pre>
  
  <p><strong>Visa</strong></p>
  
  <p>4111111111111111 = true</p>
  
  <p>4111 1111 1111 1111 = true</p>
  
  <p><strong>Master</strong></p>
  
  <p>5500000000000004 = true</p>
  
  <p>5500 0000 0000 0004 = true</p>
  
  <p><strong>American Express</strong></p>
  
  <p>340000000000009 = false</p>
  
  <p>3400 0000 0000 009 = false</p>
  
  <p>I need <strong>add Amex to the regex</strong>, I need the last two true, can anyone help me please?
  Thank you!</p>