Is it okay for my 4 week old newborn to sleep only in her bouncer during the day and with me at night??

I'm worried that my newborn will have problems transitioning to her crib, since she will only sleep in her bouncer during the day and with me at night. Did anyone else have a similar problem and if so, did your child have problems transitioning to crib?? Also, at what age did you try to wean your baby from co-sleeping.