How common is chemical pregnancy?

Lauren • M/C baby #1 in October 2015. TTC our rainbow baby. Married 10/15/11
Hi everyone, my husband and I found out this week we are pregnant with baby #1! While I am overjoyed and thankful for God to answer our prayers, I am also really scared to have a chemical pregnancy. This is my first pregnancy and I just want to have a healthy 9months. I wanted to ask how common it is for a miscarriage? I am 25 and considered in good health.