I filed a tax return and did not receive it. And it still says that they're looking over it. Can I claim it on this years tax return? My owed refund?

It was for child tax credit. I also had a baby in 2021 so I only got part of my CTC for my first child (born in 2015). It still says that they're looking at it on the website. And I even got a letter in the mail last march saying I'm due a refund. But have seen no change on the irs sight and haven't received it.