Missing subscribers

I am a rather new blogger and not very experienced yet!

I have had several people over the past week say that have subscribed to my blog and confirmed subscription via their email but it is not showing on my blog page. The bit on my main homepage where is says ‘join X amount of other subscribers’ has stayed the same number for the past week.

I have double checked myself by subscribing and confirming subscription with another email address of mine and it’s the same.

How can I fix this?

Thank you in advance!