My brother claimed me as a dependent last year. He received two stimulus checks. I worked this year. So he did not claim me but I haven’t received a stimulus.he has mine?

File a tax return with the new Recovery Rebate Credit Worksheet. This will allow you to reconcile your stimulus payments and receive any additional payment (refund).IRS Recovery Rebate Credit

• In TurboTax Online once your return is open, select Wages & Income (to enter the tax return).
• Select Federal Review at the top of the page > Continue to answer the questions for Let's make sure you got the right stimulus amount
• TurboTax will then include any stimulus amount due on your 1040 form.

There is nothing else to put on your return except your personal information if you have no income and no one else is listing you as a dependent on another return.  Be sure to have a bank card for deposit or a good address for you to receive a check before filing your tax return.

Under the CARES Act, if you are claimed, or qualify to be claimed, as a dependent on someone else’s 2019 return you cannot receive a stimulus check, in 2020.   If you qualified as a dependent for 2019, but will not be for 2020, you will most likely get it in 2021, when you file a 2020 tax return.

Note that the requirement is not just whether you are actually claimed as a dependent, it's whether you qualify to be claimed as a dependent. 

As to the $1400 2021 stimulus, yes there is a chance that your brother got that, if you had not yet filed a 2020 tax return.  You'll have to ask him.  It's not clear yet how this situation will be handled when you file your 2021 tax return.  

The round 1 and round 2 payments were based on the 2019 tax situation. However, if you file a 2020 tax return, you will receive a rebate credit for the round 1 and round 2 payments in your own name. This is not a separate check, it is part of your tax refund. It will show up on line 30 of form 1040.

The round 3 stimulus check will also be based on 2019 information if you have not already filed a 2020 tax return. After you file your 2020 tax return, you may receive a late round 3 payment or the round 3 payment may be included on next year’s tax return.

Here's some additional info on that, that supports @Opus 17  comment:

The IRS says in this document:

If a taxpayer's payment is less than the full amount and is based on their 2019 return, they may qualify for a supplemental payment after they file their 2020 return. The IRS will automatically reevaluate their eligibility. If the agency determines that they are entitled to a larger payment or the full payment, it will send them a supplemental payment covering the difference between what they originally received and the larger amount. If the re-evaluated amount is smaller, they won't need to pay back the difference. Aside from filing a 2020 tax return, no action is needed on their part.

Subsequently I also found this.

We’ll send the third payments each week to eligible individuals as we continue to process tax returns. Payments are sent by direct deposit or mail as a check or debit card.

It sounds like the IRS is in fact sending out rolling round three payments as people get their 2020 tax returns filed, although the payments are sent separately from the 2020 tax refund that you claimed on your return.