I'm getting married in 3 weeks. Five months ago when I agreed to marry my girl I said I wanted a prenup. I made it very clear, in a long conversation, in which I wrote down what I wanted and showed it to her so we could be extra super clear about what I wanted, that I wanted a prenup. Now it's come time to get married and she doesn't want to sign it. We're in final stages of wedding prep, 90 people have plane tickets and/or hotel reservations to come see us get married, we've spent thousands on deposits for housing, musicians, etc., and I don't know what to do.

It's very simple what I want. She's older -- 39 -- and the chances that we'll be unable to conceive children is relatively high. (It's unlikely, but it's not like she's 25 and children are almost a given. She just miscarried and that might affect her fecundity.) If we're together a good 4-5 years and it's clear we can't conceive, I want to get out and get another woman who can. I don't want to adopt. If we get divorced, and have invested in a house, car, and retirement plan in the meantime, I don't want to have to cut her a check for half that value (probably ~$100k, I hope) to pay back the investment I will have made in the meantime. Also, her parents are very old, and if they die, she will get a huge inheritance. I don't think it's fair that she get a check for the value of the house, and I don't think it would be fair if I get a check for half the value of her inheritance. She doesn't work (though she will be looking for a job fulltime once the wedding is over) and I acknowledge that she has give up a lot of time and effort to try and have a family (she had to move to another city where it's hard to get a job to be with me), and would be okay with paying alimony or some small-ish settlement to account for that, but anything outlandish (half the value of a house, for example) strikes me as just silly.

Any advice? I'm not a rich man but wonder what older guys who have gone through divorces like this would recommend to a guy like me in retrospect staring down the barrel of a marriage like this. I'm asking mostly for financial advice, the bullshit refusal to sign the prenup is something separate. If she doesn't sign, should I go ahead and sign the marriage certificate anyway? Will that be a huge financial mistake? Am under the gun here to figure out what to do and could use advice, on who to talk to (financial planners, lawyers?) at least. Thanks.