Needing advice ASAP

So I’m pregnant with #2 my son is almost 2 year old. I just found out I was pregnant couple weeks ago. I’m staying with my mother, and my fiancé is in another town (I’m in collage, and it’s closer for me) how do I tell my mom I’m pregnant again? I don’t want her disappointed, mad or anything. Should I wait until next week where my ultrasound is? Or just tell her? I’m in my 20’s do age doesn’t come into play. Help? How should I do this? I’m bloated sooo much I have to hide a lot under clothing.