Good or bad??

Ok so i have just jumped on facebook and one of my highschool friends has just announced she is expecting again. I also have others around me that are expecting too. I am happy for them but my heart just sank as me and my hubby have been trying for 6 months. I am desperatly wanting to have another baby and i just feel jelous that i am not pregnant yet. Am i are bad person for feeling this way? Is it a normal feeling?