Is my salah valid if i said rabbana wa lakal hamd two times because of a doubts about saying it wrong

Assalamu alaikum, i couldn't find any answer to my question about the validity of my salah. Today while praying duhr i had doubts when getting up from sujood when i said rabanna wa lakal hamd i had doubts about accidentally saying rabanna wa lakeel hamd so i said it again and after i said it i realized that i did say it correctly the first time so i dont know if my prayer is valid since i deliberately said it two times but at the same time it was a doubt so i dont know what to do.