Too soon??? Need advice!!!

Hi there! I had my first child in March so she'll be 6 months soon. My husband and I have discussed it and we think now would be a great time to have another baby. Did anyone have their children this close together on purpose? Did you have any physical problems? How did you adjust your child to the idea of having another baby around? (I know she's still too little to understand but she'll be about 15-16 months old when I have my second baby). Any advice is greatly appreciated, thank you