Once you have contracted the disease, you must complete the quest Scion of the Blood Matron to fully commit yourself as a vampire. You have 7 days to complete this quest, per UESP. The Curse of Vampirism can also be bought from the Crown Store for 1,500 Crowns. You do not need to do the quest if you take this route, as the initial disease stage is skipped and the skill line is unlocked immediately. Note: If you purchase a vampire bite from the Crowns Store, make sure that you are logged onto the character you wish to apply the bite to when you purchase it. It will only apply to that single character.
You must have contracted Vampirism before you can begin the Scion of the Blood Matron quest. If you were bitten by another player (which can only happen at an altar in your faction's final zone), a scroll will appear before you immediately afterward, directing you into the crypt under the altar. There you will find Rahaja, who will instruct you on how to become a full vampire.
Once you have contracted the disease, you must complete the quest Scion of the Blood Matron to fully commit yourself as a vampire. You have 7 days to complete this quest, per UESP. The Curse of Vampirism can also be bought from the Crown Store for 1,500 Crowns. You do not need to do the quest if you take this route, as the initial disease stage is skipped and the skill line is unlocked immediately. Note: If you purchase a vampire bite from the Crowns Store, make sure that you are logged onto the character you wish to apply the bite to when you purchase it. It will only apply to that single character.
You must have contracted Vampirism before you can begin the Scion of the Blood Matron quest. If you were bitten by another player (which can only happen at an altar in your faction's final zone), a scroll will appear before you immediately afterward, directing you into the crypt under the altar. There you will find Rahaja, who will instruct you on how to become a full vampire.
The 7 days is only if bitten by a player, which I assume is the case here. If bitten in the wild there is no time limit unless they have changed that.