Newly wed with first joint return questions, please help!?

My husband and I were recently married and would like to file jointly. I haven't been able to change my name with the social security office or state yet but did sign the wedding doents with my married name. If that even matters. Can we still file jointly? Is there a specific date that you have to be married before you can file jointly? Do i need to change my name legally before we can file? Any guidance is greatly appreciated!! im usually the one who does everyones taxes, but i am at a total loss here. THANKS!