All meds for ADHD (At least 5 years ago) are not tested with pregnancy or not recommended.
I have ADHD and stop taking my meds while in college (due to insurance changing things) what I did was focus on behavioral modifications to find ways to manage the ADHD and found it to be VERY helpful. Also if you go with out meds you need to keep your stress to a minimum, stress will make ADD/ADHD worse.
Other than behavioral modifications, make sure you don't have too full of a class load, and talk to your husband and see what he can do to help you around the home, or in general.
You will most likely want to go off the meds a few months before you start trying as they will be in your system for a while. You will need to discuss with your dr though, everyone has different severity of ADD/ADHD and he/she may have suggestions that will work best for you. You may also want to make sure you have frequent dr visits to help make sure you stay on track and work through you being off the meds and handling everything.
This is definitely a question for your doctor... I tried to look it up on the internet but the best thing to do is to definitely ask your GYN before you try to get pregnant on any medication. I was taking kolanopins for anxiety and was told that there was no way that I would be able to take it while pregnant. They might be able to give you a different medication that is safe during pregnancy.