Carleen
I've followed your plight for some time now and you've defeated the odds. I don't think this is something we can answer for you, I would rest this decision on Keith. He saved his sperm for a reason, and having children does give us a sense of immortality. If it's financially feasible, do it.
I've raised my daughter alone out of the gate and if she's had a faltered upbringing because her father has been absent, she's not telling. She's a straight A ninth grader, a varsity all sports player, popular, busy and well adjusted.
Pregnancy isn't the hard part, delivery is what causes the pain. I'd leave it up to Keith and honor his wishes. I wish the best for both of you. God bless you both.