My dad became a citizen in the year 2007. I entered the united states in the year 2012 as a minor. Recently, i was given the voter's registration certification. This means am a citizen since am eligible to vote.
No, it does not mean any such thing. Having registered to vote does not, in any way, shape or form, imply that you are a U.S. citizen and that you are eligible to vote. In most states voter registration is done simply when a person asks to be registered to vote, and the state authorities do not check whether the person is in fact a U.S. citizen. E.g. in almost all states, when you apply for a driver's license or are renewing a driver's license, you can check a check-box asking to be registered to vote and you will then be registered to vote. The state agencies dealing with voter registration are not qualified to determine whether or not someone is a U.S. citizen (they most certainly are not qualified to judge whether someone has obtained derived citizenship through parents under the Child Citizenship Act), and, under the federal law, their opinion does not count anyway. The two main federal agencies authorized to make a determination as to whether a person is a U.S. citizen are the USCIS and the U.S. State Department.
So if you really want to be sure that you are a U.S. citizen, you must apply for a U.S. passport, or file N-600, or both.
Incidentally, there is no such thing as being "given the voter's registration certification". You have to APPLY for voter registration yourself (nobody can be "given" voter registration without applying for it first, except by mistake in some cases). When you apply for voter registration, if you read the fine print on the voter registration application, you will see that you are asked to affirm, under penalties of perjury, that you are in fact a U.S. citizen.
You wrote: "My dad became a citizen in the year 2007. I entered the united states in the year 2012 as a minor."
This information is by far insufficient to see whether you are in fact a U.S. citizen. What matters is whether at some point, upon entering the U.S. or thereafter, you became an LPR (or a "green card holder"), and whether at some point after that you permanently resided in the U.S. with your U.S. citizen parent (in this case your father), being in the legal and physical custody of that parent.
As a hypothetical example, if somebody entered the U.S. as a minor and as a green card holder and then lived with his/her mother who is not a U.S. citizen and who is divorced from the father who is a U.S. citizen, that person WOULD NOT have derived U.S. citizenship through the father.
