S.C.
Hi A. -
You are entitled to feel anyway you want. The added hormones probably aren't helping. To play devil's advocate - entiquette wise it is appropriate to have a baby shower for your first child - I have gone to a few for 2nd and 3rd babies as it seems anything goes these days and basically you can invite who ever you want and if they don't think its appropriate they don't have to come.
I am always happy to go to a shower. Communication could also be the problem here. Your friends and family are not mind readers and you cannot expect anyone to know or take a guess that you would like to have a 3rd baby shower without telling them. You have to also understand that money could also be an issue for those closest to you - if they have paid for two other showers for you plus bought gifts for each baby that adds up. Not to mention all of the other friends and family showers/ weddings they are buying for. I agree it is nice to celebrate every baby - perhaps you could have a little party after you have the baby so everyone can come and meet the new addition. Another thought is throw a party for yourself to celebrate - maybe let people know that you aren't looking for gifts you just would like to get together with the girls before the new baby arrives. Hope this helps.