Contact blocked?
How can you actually see if someone has blocked you these days? I mean, there are a lot of people who check their online and last seen information, no profile picture, exclude others from their profile picture, exclude others from their status, etc. Is there another way to do this without texting or calling the person?
Try to add the person to a Whatsapp Chat group.
If the person has blocked you, it no longer appears in the membership list.
That would be, I think, another method to find out.
Otherwise, you really have to just see if the messages are delivered.