Lymphedema?

Istreett, welcome! I hope your recovering well and not too much pain. It's early yet to tell about an achy and numb upper arm, as that's not unusual this soon after node dissection and mastectomy.

You might want to consider requesting a referral from any doctor on your team to a well-qualified lymphedema therapist for baseline arm measurements for future reference, personalized risk reduction strategies, learning a gentle lymph massage you can use prophylactically, and fitting for compression sleeves and gloves to use prophylactically for travel, exercise, or any unusual activity. Here's how to find a well-trained one near you:
http://www.stepup-speakout.org/Finding_a_Qualified_Lymphedema_Therapist.htm

I hope the rest of your bc journey is smooth sailing and swell-free!
Gentle hugs,
Binney