I wouldn't worry too much miscarrying in the future, whether you take the D&C route or the pill route. They are very common procedures and if there was a risk of not being able to carry a pregnancy to term after doing so, your doctor would tell you. If you haven't already discussed your concerns with your doctor I would highly recommend it, I found it very useful when I was concerned and trying to make my own decision.
In the end I trust that my abortion (I was 8 weeks I think...maybe just under..) and the miscarriage before it will not cause me to have any problems in the future because I trust what my doctor told me. I also talked to a lot of women both in my family and friends of my family (also girls I work with who were my age at the time and had gone through it) who had abortions when they were young or older and discovered none of them have/had problems conceiving again.
If it helps a diabetic girl i grew up with had something like 5 or 6 pregnancies that ended in miscarriages or abortions(I think all but one was an abortion though) during and a few years following high school..and she now has a year old. I didn't talk to her during my decision making because I feel she's a moron in all aspects of her life, but it's a story of a diabetic to take note (i guess?).
As for the pump, I would give it a shot as you can also go back to shots, but maybe look at what your life was like, what the technology was like, etc from when you tried it before.
I tried it for 3months and decided not to stick with it because it didn't fit my life and wasn't for me but I am still open to discussing it with my endo when i start "planning" for a family though I might then not stick with it either.
In the end, it's totally a personal choice. Going on the pump doesn't automatically guarantee you're going to be in "tip-top shape", being on the pump doesn't automatically guarantee that everything will go perfectly to plan. It can in some cases improve the chances, but there's so many other factors that tie into having a healthy baby that no one can tell you going on the pump is the only thing you should do/best thing you can do.
hope at least some of this helps!! I'm really sorry again for what happened but I'm glad you realize it isn't your fault it happened and are still going to try for a baby!! =)