You know that there can be noise in the communication during correspondence via messages. Ending a text message with a period is interpreted completely differently than if you don't use it. Check out why you should avoid it.
Sending informal text messages is pretty relaxed and has no rules. However, remember the following: Never write a period at the end of a sentence in a message, as this creates doubt. While the period is a necessary grammatical punctuation in formal texts, its use in informal text messages change the meaning.
For example, if someone writes to you: "I got a puppy. Do you want to come visit?” and you answer it “Yes”, that is something completely different than if you add a period to it (“Yes.”). The last version of the answer can be given to the reader causes doubt, because he won't know do you really want to come visit or are you just being polite.