I'm 23. He's 37. I want to ttc and he doesn't. Help!

I want to start a family. My bf doesn't for another 5 years. But that means he'll be 42, me 28, when i'd first get pregnant. We've decided we definitely want 4 kids but supposedly complications in pregnancies start at age thirty so the whole age thing worries me. Any advice? I want to get a move on!