Do I have to bring my marriage certificate to do medical examination ?

I called the clinic today and they asked me to bring a marriage certificate which I will not receive it by that time because I have heard it will take 2 weeks to get it. Can I just bring a marriage license ? And why some of my friends dont have to bring it ? They said because I plan to use my husband last name, so I have to show a certificate. I cannot reschedule because I already take a day off