Trying to get pregnant...

My husband and I have been married just over a month. About a week and a half ago, he started to be unable to get an erection. We want to have kids right away, and these are my fertile days. He is NEVER had a problem with getting erections before. I think it's due to pressure of trying to get pregnant and having to be able to perform on command during my fertile window. Ha anyone else experienced this? How can I help alleviate this problem?