Why am i getting EC2 Charge during my free teir?

Hi, most likely due to this:

When using AWS Free Tier, you might incur charges due to the following reasons:

• You exceeded the ec2 monthly free tier usage limits of one or more services.
• You're using an AWS service, such as Amazon Aurora, that doesn't offer free tier benefits.
• Your free tier period expired.

Check below to find out what exceeded and how to prevent it:

• https://repost.aws/knowledge-center/stop-future-free-tier-charges
• https://repost.aws/knowledge-center/free-tier-charges

Hope it helps and if does, I would appreciate answer to be accepted so that community can benefit for clarity, thanks ;)