When everyone around you is pregnant...

L
Most of my friends and family my age are all announcing their new pregnancies.  I am truly happy for them! But I find it hard to battle my own feelings of not being pregnant and sometimes I even find it hard not to go off and cry every time there is a new announcement.  I don't know how many more people I can hear tell me "oh you'll get there some day" or "you're lucky, kids are difficult."  How do you ladies in my same situation handle this gracefully?  I get mad at myself for being so sad about others' joy.