Im getting text messages from an unknown no. from a guy.is this stalking?

i m a college student.3 months back i met a guy,who is my class mate,we gradually became freinds,then he proposed me,which i refused.after that he proposed me several times again.i refused him everytime.from a month now i m getting msgs from an unknown no.the msgs our really annoying.i hav a strong intution its him.i dnt now what to do?what is this????