Yes if u have crowding because of a narrow arch or upper jaw then u need to get an expander that will expand ur arch and make space for teeth thus relieving the crowding.The time period for treatment varies from person to person depending on the condition however on an  average an expander stays in for about 3-4 months minimum..........for more info refer the link..................http://www.identalhub.com/dental-need-for-palate-expanders-with-braces-treatment-860.aspx

If i do have to get a Expander , is there any way i can get braces and a expander at the same time ?

Kaitlinn,you can have both of them at the same time but it will depend on the type of malocclusion that u have and why the expander is being used. Sometimes, the expander can be in place because of a narrow upper jaw. Other times it may be required to create additional space. The best way to find out is to visit an orthodontist and have a consultation so that your personal situation can be addressed easily and effectively................for more info refer the link...........http://www.identalhub.com/dental-need-for-palate-expanders-with-braces-treatment-860.aspx