Buying things for baby.

Emma • My names Emma. I`m 23. FINALLY pregnant! Found out March 5, 2014 I have the best boyfriend ever! He is my everything.
Yesterday I saw this really cute bag that could be used as a diaper bag. There was only two left so I knew if I wanted it I had to get it right then. I'm only 4 weeks and 3 days today and my mom told me it was bad luck to start buying things now. It was just a diaper bag. Should I listen to her?