Checking your own credit score does not lower it because when you check it yourself, it is recorded as a "soft inquiry" or "soft pull," which has no impact on your credit score. However, when lenders or creditors check your credit to decide whether to extend credit, it results in a "hard inquiry" or "hard pull," which can temporarily lower your credit score by a few points. This is because multiple hard inquiries within a short time may indicate that you are seeking more credit and could be a higher risk to lenders. In summary, checking your own credit score is safe and does not harm it, while hard inquiries from credit applications might lower your score temporarily.