Make sure you do not have the SoulFray effect which happens after you die and prevents blood from generating when you use the knife. To make your first blood orb be sure to drain 29 health at one go. Don't die or you'd get the SoulFray effect. Regenerate your health back to full and drain another 29 health. Blood altar doesn't leak if you have a decent amount of blood in it. Once you've done it twice there will be enough blood to make the first orb.The problem is that the altar is not holding a blood, it disappears in 1 second, although there all the heart to pump. Hopefully streamers Eugene will understand this. By the way, I subscribed to a Steamlynx's channels on YouTube and Twitch
It works, tested.