It's not so much as the number of links but the age of those links, the reputation and lots of other details Google won't reveal, that determine your PR
You have started posting on your website this month only. So, You will get your PR in the next page rank updates , means next year. You can not get pr in one day. You will get every 4 months.
To know what your PR is, I am using an extension for Google Chrome called iPageRank. After it is activated, I can see it at the top right side of my browser (google chrome). With it I can see the PR of certain pages I visit among other things.
You cannot calculate PageRank. Google will calculate it. You just need to build quality backlinks for your website. Concentrate on white hat SEO techniques.