Try not to stress about it. Just because you had an abortion does not mean you can not have children and just because you miscarried does not mean you will always miscarry.
Try to relax and believe that you can and will get pregnant.

I was told when I was 18 that I couldn't get pregnant by a very stupid gp. After that my boyfriend and I had unprotected sex for about 4 years with no pregnancy I was then told that it was unlikely that the first gp was correct as he had no information to back up his claim. I was so concerned over the next few years that I couldn't have kids because of those four years of unprotected sex with no baby that it consumed me. Anyway then I got engaged and realised that I wanted to be thin for my wedding so I would start trying again after the wedding. I stopped focusing all my attention on getting pregnant and started focusing on geting healthry. I lost 10 kilos and got into my healthy weight range and started eating vegetables etc so I would have glowing skin on my big day and then out of the blue I found out I was pregnant. I ended up being 4 months pregnant at the wedding. I think that I was just so obsessed with the idea that I was blocking my chances.

I believe that you have the children your meant to have and they come when they are ready to come. Just relax and just focus on getting your body a healthy as you can so when you do fall pregnant you are the healthiest you can be for your babies sake.
Good luck