TTC #5 and feeling like it will never happen

My hubby and I have been married for 12 years and have 4 beautiful healthy kids (10,8,7,3) we are currently in the process of getting married through the church and have gotten a lot closer to our faith and religion. We plan on a Nov 2017 wedding and have been TTC for about 3 months now. Since I don't want to be pregnant at our wedding I'm hoping that it happens soon. I told him that if I don't get pregnant by next month we will have to wait till after the wedding. He brought up a good point though... we are getting older. He is 37 and I am 31. We've never had a hard time getting pregnant. But I know It's Gods will and what he has planned for us. We have 3 boys and one girl and would love for our next blessing to be a girl! My daughter tells me almost every day that she wants a baby sister. Would like to hear from anyone that might be having or had the same experience. Thanks.