To check your vote power % you can goto steemworld.org/@jnrlouis
To see how much your vote is worth right now goto https://steemnow.com/upvotecalc.html and adjust the numbers on the left.
Your vote may say it is worth 0.00 but it is actually worth 0.0038
It will go up and down based on the price of steem.
You should vote because you will get curator rewards and as the price of steem increases the votes you have already cast will go up or down. So the 0.0038 vote will be worth 0.0076 when steem goes above 6$