Which way to di tan at 19 weeks pregnant?

My wedding is at the end of May, as the bride, in as stark white dress i would like a tan, if i were just the bridesmaid, or just for a nice summer tan i would get over myself and go without for 9 months and be happy. but as the bride, and as i will have to buy these pictures, and look at them the rest of my life i would like to know a little more. If i lay out in the natural sun and make sure i moisturies, and keep cool i will. if this is ok. if not id like to get a spray tan (ive never ever liked the beds) i need to know what questions to ask I.e. what chemicals to make sure are not in the formula of the spray to ensure i dont hurt my little bug. I am 19 weeks and 3 days with my first child. my wedding is at the end of May. which method do you suggest. id like to do it as natural as possible for both our sakes but i dont want to "cook" him!! i need help and quick. thank you.