I have a friend who had two girls when i had my first two boys, she was slightly younger than me, i was 22 nearly 23 with ds1, 26 with ds2. Although i was considered a really young mom and didn't have many other friends pregnant with me, most are only just expecting their third.
I think age aside, if you prone to boys you are prone to boys regardless of age (i hope at 30 age would be in my favour now but it turns out you'd need to be closer to 40 to have age in your favor and even then boys still happen). Swaying though will counteract this if can make your fertility lower and lower his sperm count. I was convinced this was ds4, totally shocked when i heard pink, i am convinced that would not have happened without this site. Good luck x