The best and simple way to check whether you are blocked is to check either without an account or from another account.
If you have an alternate account, you can look up the person who has blocked you; if you can see their profile and everything looks the same or the person has even updated their content, then that instead, unfortunately, means that they have blocked you on Instagram.
The most straightforward way is to check from another account. Suppose they have blocked it but can see the same account using an alternate Instagram profile. Regardless of why they blocked you, you will know you have been blocked if you cannot find their profile while looking through your default account.
If you have found out that a specific person has blocked you on Instagram good chance for you to meditate on why exactly you were blocked and whether your behaviour put off the person who blocked you in the past.
It can be a rather embarrassing situation to face since being blocked means that it was your own fault one way or the way; you might have insulted them, misbehaved or offended them with a post of yours.
Regardless, keeping a good profile in the long run for your casual and professional needs is essential.
Now that you have learned how to know if someone blocked you on Instagram, will you reflect on why you had to look this up in the first place?