Why do I have rough edges on my porcelain veneers? Could they be chipping already? I've only had them about 6 months, but when I run my tongue across them, they feel rough. I know porcelain isn't all that strong, but I don't bite anything with my front te

Yes. Have your dentist check on that and may be have them fabricate a night guard for you.
Polish. The most likely cause of this is that they need polishing check with your dentist.
It . It could be that the porcelain is chipping but just as likely there is some cement left over from the bonding process. I would check back with your dentist so he can take a look. Be careful with those veneers! if your dentist didn't make you a nightguard, i would ask if it is something he recommends for your specific case. Often patients are very careful with their veneers but not so much when it's out of their control (when they sleep). Good luck!
Possible. Have your veneers always felt rough or is this new? If its a new problem, get them checked right away. It's possible you move your teeth against them in your sleep. If its always been there, ask your dentist to repo lush them.
Get them Polished. Did the dentist adjust them a lot after placing them? That could have caused the roughness, in most cases you can go back and have them polished.
See your dentist. I would see the dentist who placed them. It may be that simply polishing the edges is all you need. There may not be any porcelain damage at all. Please go and see the dentist.
Probably wear . If the edges are rough, then you either chipped them, some bonding is still stuck on those places, or you are feeling a junction line between tooth and veneer. You should be wearing a nightguard to protect them , and a day guard if you grind during the day. This can be as simple as a whitening tray type material.