Thanks for writing to us with your health concern.
Some amount of pain and discomfort is common within 4 - 6 weeks of surgery, but it should not be incapacitating.
If the pain is so bad, that you cannot work, then there is actually no point in going to work, is there ?
If the Advil
makes you feel better ( if the discomfort is within the range of normal , then it will ) - then you can definitely put it off until Friday.
To me, it does not sound like something emergent, and I think you would be better in a couple of hours ( rest too is a must alongwith the medication - take a hot water bottle to bed for 2 hours ).
If the symptoms just do not relent
, or in fact, worsen, you must unfortunately call off at work and go and see your doctor.
All the best.
Please feel free to discuss further.