34 weeks and 4 cm dilated

I've had very easy pregnancy, no complications so I was shocked when my dr checked my cervix today and told me I was 4 cm dilated! She didn't seem overly concerned and just told me no heavy lifting and to go back in a week to see how things have progressed. First time mom here so curious to see if any of you other ladies have experienced this before and how long you were able to keep your little darling cooking once you were dilated!