Nervous

My husband and I found out on Tuesday that we are finally pregnant after trying for 2yrs. Per my calculations I'm exactly 4 weeks. We are super excited but I am super worried at the same time I am feeling like something is going to go wrong or maybe the test was wrong. Even though my cycle never showed i can't shake the feeling. I'm 38 and my youngest child is almost 10, so I'm feeling like a fish out of water right now😩😩😩 I don't know how to shake this feeling and my appointment is 4 weeks away!!!