Thank you for your question.
It is unclear whether you mean last month as in 6 weeks ago or longer. Pregnancy is an important cause of a missed period but there can be others too. I would suggest that you see your gynaecologist for a complete history and examination to determine the cause and thereby correct treatment. This is a common problem and if it happens occasionally it is nothing to worry about However if periods are delayed frequently your doctor can help solve this issue.
hope this helps