If you think you might have a vocation, then you might. When asked that question by my daughter, the sisters at the convent just said you know. And they also said they knew that really wasn't very helpful.
If you think you might have a vocation, contact a seminary or convent. If they are reputable and Catholic they will help you truly discern a vocation as a nun, brother, or priest (you don't say if you're a boy or a girl). If you don't, you will discover that too.
I would recommend going to the CMRI website. (I was unable to post the website link here. Apparently it is not permitted, but you can probably figure it out if you try.)
There are vocations links on the sidebar.