Hello shauna_schwab, we are sorry that the time is a bit too tight, it is unable to reach you before 18th May if you order it now.
*If you order standard size now (about 3-4 weeks making costume time) and use the fastest shipping method (Premium Express, 3-6 days shipping time), it will reach you around 4-5 weeks after order's confirmed.
*All shipping information (including methods, cost & estimated delivered date) will be shown in order page, before payment; you can pay extra cost to upgrade shipping method there.
*Please remember to mark down the date (you need it) in the order form when you order it. :)