I was 25 when I gave birth to my daughter.
Even at that age I was the first out of all of our friends and family to have a baby, so I fealt pretty isolated, and it wasn't easy. I hadn't been planning on having any babies for years and years, and also lived pretty far away from my parents- which didn't make things easier.
As soon as you find out you are pregnant, your life changes entirely, and the days of only having to worry about yourself are pretty much over for ever.
On the bright side, by the time you are 30, and all your friends have little babies, or small children, you will have a big grown-up 13 year old, and you will have more freedom then your friends will.
You will be able to travel, or do some full-time study, or pretty much whatever you like by the time you are 45 - and believe me, a lot of your freinds will still be helping with homework, reading bedtime stories and packing school lunches. (there was a woman in my first time mothers group who was 43 !!!! By the time i'm her age, my daughter will be almost 20 years old- imagine !!!!)
so it does even out a bit in the end, you'll be close in age to your son or daughter, you'll be able to have your own life again while you are still young enough to enjoy it, and some time far in the future, you'll be young enough to see your own grandchildren grow up too.
Plus, your body will recover easier after the birth than an older mother, you'll have more energy to chase around after your child, and probably will be able to deal with the loss of sleep etc. Better too.
It's not all bad !!!!!
Take heart, and concentrate on the benefits. You can smile to yourself when your friends are still emptying potties in their 30's!!!!!