Yes its going to stretch like crazy if you don't have a light in place. soaking seeds is mainly to get the tap root out but its not going to make leaves without light. the warmth and rays of light will help the seed know which way to go.
3 days with no signs of sprouting is still normal. Keep the rockwool evenly moist (not soaking wet) and maintain a temperature of around 22–25°C. Light can be on already, but patience is key!