Have a couple of treat bags, all but one is filled with a special treat. (Think small piece of candy or something similar.) The last bag will contain your pregnancy test or a note announcing the pregnancy. You can have party guests each choose a bag to be opened with everyone or if you're doing this with just one person, they can open the bags until they get the pregnancy test results. You can be a bit more creative and ask trivia questions to "earn" the goody bags.