Correct, you should not be concerned.
Time in market is more important than timing the market.
Remember that when the market falls, you have not lost money, not unless you sell. You may even judge it to be a good buying opportunity since you might assess the new lower price to be more reasonable. Over time, a diversified portfolio will expand in value due to compounding, unless you are not a believer that the future will be better than the past.
Take a look again at the charts - they spell it out clearly.