Are you kidding?
So someone isn't allowed to get pregnant and has to stop TTCing so that they don't end up with a due date near someone's wedding!!!!
I am hoping you are the pregnant person who is nervous about her engaged friend's reaction and not some loony bride-to-be! If you are the pregnant person and your friend has reacted badly she is off her rocker and you really shouldn't feel badly.
If you are the bride-to-be, you may feel miffed for 20 mins as you visualized your friend there but GET OVER IT and be happy for her.