If you can find another job that will hire you and you feel up to it, I say go for it! As long as your doctor hasn't given you any restrictions, you should be ok. Just make sure you take frequent breaks and aren't over working yourself. No heavy lifting of course. Save up all the money you can, especially if you will be on unpaid maternity leave and dad isn't helping financially. Good luck!
The best thing you should do is talk to your doctor about it. You don't want to overwork yourself. If you can find a job where you will be sitting most of the time that will be perfect. Just don't over work yourself it's always good to be independent when it comes down to providing for you and your child but its always best to get that support from your family especially if they are willing to help you out.