Give me a test public key whose private is known to you. Go ahead and generate a private key at bitaddress.org. Post here its UNCOMPRESSED public key. I'll return you another public key whose Private Key will be next to your private key. like this.
If your private key (in decimals) is 66899805185916575564669809333844135879224147665865100807356278765935415566327
I'll give you the public key for the private key 66899805185916575564669809333844135879224147665865100807356278765935415566328

You can counter check by putting private key hex at here https://www.mobilefish.com/services/cryptocurrency/cryptocurrency.html