how do u know who is ur twinflame??

Twin flames were created together in the beginning and share a unique destiny.
Twin flames are much as twins born of the same egg. This would be from the same soul source. There is not of that kind of twinning going on. This is different than soulmates. Twin flames would be of the same soul energy source and would have been decided at what you would term the creator source level or at the higher-self level, which we see as a level at which a being has the ability to create seed selves in 3rd-dimensional reality.
Similar to when twins are completely separated at birth and they find each other after many years and discover that they have the same food tastes, the same odd way of smiling and the same tastes in clothing (I'm born one a twin). With twin flames' being born of the same spirit, when they unite physically in 3rd Dimension. Your twin flame knows you whatever life you are expressed. But each with the same pattern of divine identity.
Though they spend some lifetimes together and others apart, their tie is eternal, and after they have each united with their Higher Self they will be together forever.
All though it may sound like a beautiful match made in heaven relationship, there is a thin line with this connection and deep intensity, that as beautiful and perfect a relationship can be, this can sometimes be a total opposite, spiritually when you enter in this life time you know if you want to meet with your twinflame or not and you know all your life you must prepare yourself to be able to join with your twin flame, it is not an automatic, it is truly a privilege to know your Twin Flame but you must be ready. You will have to learn to love deeper than you ever thought possible and that usually means meeting, with a twinflame connection you have to be brave and strong enough to be able to risk loving with your heart and soul that there is also a fear that dream may be shattered just as experiencing pain as well as joy.
When Twin Flames come together they become one, they are the mirror image of the other. They think alike, they hold the same values and often their life experiences are very similar.
No matter what, if we are to be with our Twin Flame then it will happen and by experiencing the loves placed before us by Spirit and if it is part of our karma. A book & movie (what dreams may come) was created based upon twinflame/twin soul connections. (this is one of my favorites) the general meaning to twinflames was expressed here.
A soulmate connection is different from the twin flame. We have only one twin flame, we have many soulmates. Soulmates are life partners, close friends, co-workers, a teacher, anyone who influences your life one way or another. They play the game of third dimension with you. Companion Soulmates are trying to develop the same chakra energy, these are the relationships that are certain family members or friends who are there, when you need them most. True soulmates tend to be harmonious and satisfying, but not as intense as a twinflame but can accomplish great things together as well as a life partnership even when there is negativity or a spiritual confliction in between them, nothing can separate this connection they will always be connected and feel the need to be there for one another.
These closely resemble Twin Flame connections a relationship based on romantic love, however there is still karma between two people and the couple can learn to live for many years together as a beautiful relationship and then there are the types of soulmates who come together for a reason, making some type of impact on a person's life. in some cases the relationship ending in a separation, divorce and later to find there was a reason for it all happening the way it did, keeping in mind not all romantic relationships are True soulmates