I don't understand

I am 7.5 weeks pregnant and my husband and I are so excited and happy about it! He told his mom right away because he couldn't keep it in. She was thrilled!  I haven't told anyone in my family because I'm not sure how they will react. My husband and I married pretty young (21) but we had been together for 3 years. Now we have been married a year in May, my husband has a steady job in the marine corps and I have completed my associates degree and have a job. We live across the country from our family and have made a great life for our family. So why am I so nervous to tell my family and what their reaction will be. I know they will love the child once it's here but I just fear they will have they same reaction that they did when we were getting engaged. I need some ideas to break the news