Okay... I said this very thing in another thread: T does NOT cause one to die "early". It's a very common, and fairly vicious, misconception. What testosterone does to the "female" body, in terms of longevity, is gives you the same propensities as per physical health as you would have had had you been born male. Hence, you don't have much to worry about as far as dying young, unless all the women in your family lived into their 80s or further, but all men die by 40. Barring that sort of thing, you should be fine. People will tell you that T ups your chances of heart attack or disease, that you'll end up with cancer or liver damage, but under the proper medical protocol, you'll be fine. This is the reason we ftms need to see a doctor at least once a year for blood tests--- they check liver toxin levels to make sure the T isn't affecting its functioning, cholesterol levels, and blood pressure (obviously, not via a blood test), because T can cause hypertension, though I've never heard of that happening without the person already having a genetic predisposition toward it. If you keep your "female" organs, you'll need to have a gyno exam once a year to make sure you're not at risk for ovarian or uterine cancer--- just like any other genetic female would. Basically, if you're not a moron who gets his T illegally (without a doctor's scrip), eschews doctor's appointments in general, and doesn't take care of his health, you'll be fine. You don't need to worry that you'll die prematurely, or that you're shooting yourself in the foot by trying to be fully yourself.
Now, as far as pregnancy, I can't tell you much more than the other guys have. I'm currently going through a divorce, but when I was still married, we talked about having kids, and I worried about how T would affect my eggs. I looked into freezing them, but it's upwards of $8K to do that, and you have to go through an extensive female hormone regimen to prepare the eggs for extraction. It's not a pleasant process, from what I can tell. If you don't freeze them prior to going on T, they'll stay where they are, as long as you're not planning on hysterectomy or oophorectomy. Thomas Beatie was on T for 5 years prior to bearing his two daughters, and as far as anyone's aware, those kids are fine. Like someone else said on here, there's really no research to tell us what happens to eggs when exposed to T... and I guess, if you choose to go on T and get pregnant later (or use those eggs otherwise), that's just the chance you take.
Also, as other guys have said, it's REALLY tough to go on testosterone and then stop, unless for some reason you're one of the tiny percentage of guys who has a bad reaction to it. Usually, in my understanding, those few have reactions to the oil in which the T is suspended, or some other random thing, and that can be corrected by changing the method of delivery. I've had to go off T twice, and it was excruciating for me. Whereas prior to going on T initially I thought I could possibly bear my own kids down the line, there's no chance of that now. I like the way T makes me look and feel, and I wouldn't take it back for anything. That said, I waited a year & a half after going full-time to starting T because I was one of those guys who thought I could do without it. I was wrong.
Hopefully this helps a bit....
SD