Does a hormonal imbalance affect how a pregnancy progresses?
Can conception even occur if you have an imbalance?

Fertility certainly can be effected due to a hormone imbalance... one of the more common reasons for infertility. If you feel you have an imbalance, or if you know for sure that you do, best to check with your doctor or midwife as there are a number of ways to help you get back on track if need be... some herbal, some medical depending on the specifics in your situation.