Common Law Marriage
A couple does not have to have lived together for at any length of time in order to be considered common law married. Contrary to conventional wisdom, there is no time frame that qualifies a couple as husband and wife.
Here is the biggest, most important factor: Heterosexual couples who hold themselves out to the public as being married—are married. So if you call him your husband to your family and others and he does the same—you are likely married.
By the way, there is no such thing as a common-law divorce. If you are married, whether by common law or statute, you must then obtain a dissolution of marriage if you wish to no longer be married.