There is nothing you need to do if you get a tax topic notice #152 on the IRS Where's My Refund site, it is completely normal.
Tax Topic 152 is just a generic message from the IRS letting you know that your return is still in the processing stage. The IRS estimates that most refunds are issued within 21 days once your tax return is E-filed, so as long as you are in the 21-day time frame, there is no need to worry.
