Traveling while pregnant

So I'm 18 & I'm 12 weeks pregnant tomorrow. My church is traveling to Poland in August and my grandma has been saving up for me to go for the past 3 years. The tickets are about 3,000 and we have 2,500 already saved. However I will be around 6 months pregnant when it's time to go on the trip. So, I guess my question is.. (Bc I haven't told anyone I'm pregnant yet) what should I do? If I don't go we lose all the money put into the savings and they split the money to families who do not have enough to make it on the trip. I really don't want to be giving all the money my grandma and I have worked on so hard on just to not even go.. But what do ya'll think?