It's perfectly normal to be worried. I think every one of us has at least one fear deep down, when it comes to diabetes, and usually more than one. However, I'm happy to say that there's nothing to do with diabetes itself that will make it harder for you to conceive. There are other conditions that a lot of diabetic moms also have, things like PCOS for example, that do have an impact on conception, but that's not due to the diabetes itself, and plenty of non-diabetic moms have those problems as well.
Have a look through this pregnancy section and see all the type 1 moms that have conceived and delivered healthy, happy babies. In fact, the reason most of them aren't around on the forum right now is because they're too busy off raising their families! So it definitely CAN be done and don't let anyone tell you otherwise! Being pregnant with diabetes is hard work though, you have to keep your numbers a lot tighter than you usually do - and in fact you need to start doing that before you ever try to conceive in the first place. But as long as you have good control and get proper prenatal care it is absolutely doable!