Should I wait till 6 months to leave the house?

I want to get your opinions and vote. I have a month premature baby and she hasn’t been outside since we brought her home from the hospital. We have a doctor home visit for her shots and physical checkups. She only use ready to go formula and disposable nipple. But my husband has been saying I’m really overreacting on things. He was married before me and has an older son but he was full term and mine little one is not. I’m a first time mom and I’m very scared and worry about my baby health. Am I overreacting or am I doing what any mother would do? I really want to take my baby outside for a walk in a park but don’t know what to do.