Once I had 2 girls, and we had the ultrasound for the 3rd I knew she had to be a girl. I knew about girls. In a lot of ways, it is sure nice to have the same sex. My girls are as different from each other as can be - one is a Straight A student taking classes a year ahead, the next is ADHD and LD, and the third is "average" - a B-B+ student. But they are still girls, and do "girl" things. Being a member of a still very heavily male dominated professional (computer nerd) I was determined that my girls would not be slotted because they are girls. I brought them tools and trucks along with their dolls, and you know what, they would never play with them. I never believed until seeing it with my own eyes in my own house - that girls are girls from the moment they are born. My nephews came along, I tried to get them to play with them - no go. There are basic differences between the sexes from day one. On the other hand, my oldest daughter has the highest math grades of anyone in her class. She is in 8th grade and taking 9th grade math. She is 1 of 3 kids in class doing this. My whole point is - CONGRATULATIONS - and you at least have some idea what you are in for. So, you have some idea what you are in for with another boy, but remember they are not the same kid. Enjoy.
Congratulations again.