Kaiwho,
You would know better than anyone else. Have you been sharing links on social media? Has another site mentioned yours in a blog post or on social media? Have you done anything to your site that would cause people to start visiting it? Do you have links in a signature on a forum somewhere? Check your referral reports in analytics and see where those visits came from. I doubt anyone here will be able to tell you why you have a spike in visits without more information.
Best,
Shawn