Unsupportive " friend"

So I have this friend who is super rude to me she just keeps coming at me making me feel so bad about myself and making me feel like I'm not gonna be a good mother like I won't be able to provide for my child. I met my fiancé 3 years ago we were friends best friends more like he was there through every failing relationship and stuff we started actually dating almost 2 months ago and I got pregnant last month I moved in with him she's telling me it's too soon and it's a mistake but I don't see my child as a mistake at all and it really offended me she would even say that do I have a right to me mad? Or am I over reacting?