Need advice!

Hi all! I need some opinions on a matter that I am torn between. My husband and I have been trying for 10 months now, not long I know. We have a beautiful 3 years baby girl. We have won a trip to South Africa for anytime before the end of 2019. I am debating getting back on birth control because I don't want to be pregnant on the trip or get pregnant the month before we leave and there aren't options for postponing the trip if I do get pregnant, once we pick dates we are locked in. The thing is once I get back on birth control I don't think I'll get back off of it. I can tell my husband is disappointed but trying to be supportive. I don't really want to give up trying but I'm truly torn. What would you ladies do?