My front bottom teeth hurts and i just got top braces last week why do my bottom front teeth hurts ?

Change in bite: Your orthodontic appliance have started changing your bite, so that might be the culprit. Could even be referred pain. Then again, without an exam, radiographs, or even knowing your age, it is impossible to tell for sure over the internet. You should ask your orthodontist.

Hard to say: Hard to say without knowing your situation. May or may not be related. Discuss with orthodontist.

Pain: Can be from pressures caused by changing your occlusion. I assume you are seeing an Orthodontic Specialist. The Orthodontist can explain the changing relationships in your mouth, the potential for destabilization of teeth in the other jaw, and what can be done to provide relief.

New Braces: wearers may have sore teeth for a week or so after getting appliances. Your mouth is getting used to moving around. Once that happens the discomfort following future adjustments will be much less and usually only for a day or two. Soon you'll start noticing the changes in your smile! You didn't say your age but you can take a Motrin or ask mom for a Tylenol to help you through the rough patch.