I need some advice

Okay everyone, I need some advice. My husband and I are seriously thinking about having another baby before I get too old. I'll be 38 in May. My kids are 16 and 13, so there would be a big age gap.

We will have to pay a lot of money to even try, since I had my tubes tied 13 years ago. I would need an operation to untie them essentially (put them back together), then there are no guarantees that it will work. I was very fertile in my 20's, but the older we get the less fertile we are.

Then I'm not sure I am even a candidate for the surgery. Only certain kinds of tubals can be reversed. I have to have a test done first to see if my tubes are still patent.

Insurance will probably not cover any of the tests or surgeries, so we are probably looking at a few grand (7-10,000).

I am really hoping you guys can help me decide on what to do. I know we both want another baby, but are we just being crazy?

Thanks for your help.