Another person in my life is pregnant!

So after trying for over 2 years, a girl that works for me got pregnant. She just had her baby boy in early August. Yesterday, my Assistant Manager came into work and told me that she is pregnant too! I am very happy for her, but I can't help but ask "why not me". I am older than both of them, they are both in their 20's and I am about to be 33. I know that I am not considered "old" but it is so hard to see everyone in my life keep getting pregnant with ease and I have to go through so much!