Communications Officer Justin Lavelle of BeenVerified.com shared how to tell if someone blocked your number.
If you have an iPhone and the person who potentially blocked you does too then you should look at your last text from that person. The last text message should say "delivered" at the bottom. If that person has blocked you, you won't see the "delivered" notification under any new texts.
Or if you call a certain number and it goes straight to voicemail or you get a weird message like "temporarily out of service" or "the person is not taking calls," it could be that they've blocked your number, says Lavelle."
If you have an Android, it's a bit more difficult to tell if you've been blocked. Your best bet to tell is if you've receive a strange message (see above) when you call that number.
Has anyone blocked your number recently?
SOURCE: Reader's Digest