When did you find out the gender of your baby??

No one gives a sh*t but you. And there are only 2 options. So it's not really interesting for anyone.

I had nine babies and found out in the delivery room.

I found out when she was born and the doctor greeted her by the girls' name I had chosen.

If you choose to hope to find out in advance, nobody here can tell you when that will happen. Most doctors offer a routine ultrasound at around 20 weeks -- but that scan is to check for anatomical abnormalities and there is no guarantee that the genitals will be visible.

Not clear what a 'gender reveal party' is, or why you think there is any benefit to having one. If you have close family and friends who are dying to know the sex ASAP, you can call them and tell them when you find out, or email them, or post it on social media. (But here's a dirty little secret -- most people you know AREN'T dying to know ASAP, and are likely to feel put out at being invited to yet another party where they will feel obligated to bring a present.)

I found out when my baby was born.