Pregnancy and your first

Anya🕉 • 🐾24 ; mother of two, soon three💓 girl mom
Is it normal that the thought of having another baby right now (happy aswell) makes me feel sad and like I am going to miss my daughter I have now? She is 2.
I can't quite explain this feeling,
There is a Chance I may be pregnant, and I am happy and nervous. And now I am feeling sad. Had to go and kiss my daughter while she sleeps. It almost feel like when you know you're going to have to say goodbye to someone for a while. I really don't understand this feeling and I know it's irrational and doesn't really make sense. But has anyone else get this ? Can someone explain it to me ?