Partner is a debby downer

Anyone elses man refuse to get excited and doesn't really talk about the pregnancy, because hes so worried it's early days?! I am going through it with fatigue, sickness, headaches, concrete breasts of unbearable pain (not even being dramatic lol!) As im sure many of us are, but he is just like 'I'm not letting myself get carried away just in case'. We have started telling family because im so sick its very hard to hide and his parents gave him this big speech about how they should be the only ones to know. I have a very large immediate family, 7 siblings step parents and i plan on telling them today as agreed but he is so grumpy about it! I love him to death, weve been togerher 11 years, I am just so excited and if the worst happens then it does but this is our first and i just think we should enjoy every second.... How can I change his mind set?! Sorry, HUGE rant lol