The only thing i would encourage you to do, if you are concerned about finances and you are currently entitled to maternity leave, is to look into the rules regarding when you can leave. I had to leave early (at 16wks pregnant) due to severe morning sickness enhanced by the high-level stress of my job; and because I left so early I wasn't entitled to my maternity leave I had accrued. I know money is not the end of the earth and definitely my child & my own health will always be my first priority, but I lost out on about $5,000 and a guaranteed job after a year's break.

At the end of the day though, you need to do what's best for you & your child!