Trying again

I just got my iud back out for the second time to start trying to get pregnant, the first time just over a year ago I gave up on trying and put back in my mirena. It just wasn’t happening and I was getting way depressed and was tired of feeling like I was failing. I’m scared this time will be the same. I have a 3 year old already and I want to give him a sibling so bad but I don’t know if I can. I don’t want to disappoint my husband again because he is so excited about the thought of another baby.