Jealous of people "more" pregnant

Jen
Hi you guys. I feel really badly. Thank God we are 13 weeks pregnant with what is so far a healthy pregnancy. I have a number of friends and family members (mostly younger, not that it really matters), who I spoke to while we were trying (and going through treatments etc). They had shared with me that they were also trying. I am inexplicably jealous of all of these women who got pregnant before me. Like my sister-in-law who is now almost due, my friend and 20 weeks, and my friend who is just 15 weeks.. It doesn't make sense! I'm able to tell them I'm pregnant too now, and I'm so happy for them! But somehow I'm internally upset that they are "more pregnant" or that they beat me to it or something. I know it isnt contest, and I feel SO blessed to be carrying this little one and to have a wonderful husband, but I'm having trouble shaking this feeling. 
Any advice? Thoughts?