I think that waiting marriage is a very, very important role in this. It is always your decision, depending on your situation. Do you have a stable career? Partner? How will you take care of your other two kids?
This is a big strain on older children to have another child come into the picture who needs your full devotion. It can cause a lot of jealousy and acting out. Think about this. How will you help them deal with the new baby?
You will need to carefully plan out everything for this new baby. Make sure your money is in the right place and that your other two children are stable, themselves, and that you can get someone to help take care of them while you’re out for recovery.
It’s A LOT of work and planning… but if you aren’t ready to those, then you don’t need another child.
Best of luck to you! I hope you make your right decision.