Hm? Need opinions

I'm moving in with my so. 
I'm scared to tell my mother, though (I'm 21 years old). Because she doesn't like him. 
For no good reason, also. I feel as if she will throw my son (he is 5 months old) in my face saying that I shouldn't depend on my so and blah blah. I have a job though, so idk? 
Should I be afraid?