You can file an I-526 petition whether you and your husband are in the US or not. Once the I-526 petition is approved you can then apply for conditional permanent residency at the US consulate in your home country. Also, you and your husband cannot remain or live in the US if you are out of status. Please note, if you leave the US after you have been unauthorized for more than 6 months in the US you will not be able to re enter the US for 3 years.