Announcing our pregnancy?

So hubby and I have been together almost 6 years. Have 2 beautiful babies and just found out we’re expecting baby #3. We actually had both decided to “try” this last month and with Gods will we actually conceived. Our kids are almost 4 and 1. This baby and my youngest will be 22 months apart. Hubby and I have always said we wanted 3-4 kids. We got pregnant with our first child unexpectedly and I was only 19, still lived at home, etc. idk why but just the thought of telling my mom that I’m pregnant makes my stomach flip and I can already hear what she is going to say... I’m literally 25 now and I can’t seem to get the thought of “disappointment” out of my head. My husband was talking to me about it last night and it kind of eased my mind. Like we planned this, it’s our family, we’re obviously financially secure, we have a space for another baby in our home/vehicle wise. It just sucks and idk how to get the anxiety of telling my mom to subside. Just the other week (before I had found out I’m pregnant) I had a crazy dream of being pregnant with my sister. I called my mom that day and was like just telling her about this silly dream I had and she was like “wow! Like that’s all you need! Either of you. Maybe someday... WAY down the road” Now that’s just all I keep hearing in my head. I haven’t even told my daughter yet which is the 3 year old because I don’t want her to accidentally tell my mom. I know my daughter is going to be so excited too because she actually said for Christmas she wanted to ask Santa for a baby sister because she already has a brother and she wanted a sister ❤️ just kind of venting... does anyone have any advice or has anyone else been in my place so I don’t feel so alone and stupid...?