No, you're not married just because you live together.
Only a few states recognize common law marriage. Although the exact rules may vary slightly, they generally require 3 things.
1. Agreement to be married.
2. Acting in private as if you were married (like living together, having joint accounts, etc.).
3. Telling other people in public you are married.
Some states may have other requirements, such as a minimum time you must live together.
You said "bf" so you seem to be missing step #3. If you want to decide that you are common law married then he is your husband.
If you meet the tests to be common law married, then you are married for all legal purposes. You MUST file a married tax return (married filing jointly or married filing separately.) You must file as married every year, you can't go back and forth. You must tell your employers you are married, since it may affect your work benefits. You must tell the state that you are married if you receive public assistance since it changes your eligibility. You can't split up without a full legal divorce with judges, custody orders, alimony, lawyers and everything else. Married really means married and is just as legal and binding as if you had a religious or civil ceremony.
If you want to be common law married for 2016, then you are married, now and forever, in sickness and in health, as long as you both shall live, or until you get a legal divorce. It's not a casual step. Make sure you know what you are doing.
