help please ladies!

Na
I'm 26 happy married and with a 20 months old girl, we just found out that I'm pregnant and I really don't know how i feel i know that a baby will be always a blessing but sometimes I feel like it's too soon to have another baby that my baby girl it's too little to have a sister or brother, and I feel anxious and nervous it's just not like my past pregnancy... why I'm feeling like that ? Anyone else? Am I wrong?