The nanny attachment issue...

I know this sounds silly, but I'm actually concerned. The nanny started last week and although I work from home and try to see my 4 mo old baby boy anytime I can, I have already noticed that with her he feels very comfortable and doesn't miss me. I'm starting to worry, whether he will grow very attached to the nanny after some time and forget about his mom, ex-primary caregiver. He is combofed but has now completely ditched breastfeeding. I was hoping that we would have that one thing to keep the special bond, but now I feel like I have nothing special compared to our nanny (who btw is great, a true natural, but she told me last week how one of the babies she used to take care of now loves her 'more than her own mom' and gave me the creeps. Fuel to my fire fr). Does anyone have any experience?