Not excited about 2nd pregnancy

Hi mummies. My firstborn is currently 13mo and I found out that I'm pregnant with my 2nd. It's not a surprise because we did plan for it. However after finding out that I'm pregnant, I don't feel excited at all. In fact I'm a little sad. Sad that my time with my firstborn is limited. Now I feel like I'm knowingly taking away time and attention from her. I'm scared too. How would I be able to handle 2 kids under 2? Is this normal? My husband simply just brushed it aside and told me not to think too much.