Unwanted Comments!

I have alot of extended family that I don't see alot of. So my facebook keeps us connected. We are a close (BIG) extended family but some members are provinces away. But I also have my spouses family and some friends on it. My spouse and I are finding out the gender at our first ultrasound this Thursday for the "big" anatomy scan at 21 weeks. I posted how excited we are and I am SICK of getting comments (also in person) about how we shouldn't find out, it shouldn't be allowed, why can't women now a days wait. One of his family members went as fair to get into that "it saddens her we want to know". And "why ruin the suprise, there isn't a feeling like when the doctor says it's a ...". Honestly with my first, we had complications after a 32 hr labour so he was rushed away to the nicu right away. So there was no "moment" just chaos. Can anyone give me some fast remarks to make to these people!? Or jabs!? It's annoying already!! This is our desicion.