Achy feeling in one leg for 2 days. Starts mid calf on outside and runs down leg. Seems to bother me regardless of activity.

Get medical checkup. If this aching is persisting, you should get a medical check right away as therr is some risk of blood clots in the calf veins. It is easy to check for it with the help of an ultrasound. This should be done ASAP, like on Tuesday(tomorrow) if your doctor can fit you in his/her schedule. otherwise go to an emergency room for med checkup.
Nerve pain. This may be referred pain from a spinal disc or spur pressing on a nerve root in your lower spinal area. This is similar to sciatica. If the discomfort worsens or doesn't resolve after a week or two,see your physician for evaluation and possible referral to a neurologist or neurosurgeon. In the meantime take Tylenol (acetaminophen) or,if you can take them, nsaids like ibuprofen or Aleve.