3 weeks after Blepharoplasty my right side upper eye looks different from left side, is this normal? (photos)

It is not unusual for the eyelids to heal at different rates after blepharoplasty.  Sometimes there is more swelling on one side than the other or more bruising on one side than the other.  There would still be some expected swelling present at 3 weeks after surgery, so I wouldn't be too concerned about any difference in appearance between the two sides at this point.  I would give it a good 3-6 months and then see how they look.   

At three weeks after surgery, it is not possible to know if the ptosis will persist.  Minor eyelid asymmetry is normal immediately after upper eyelid surgery.  Much of this is related to small differences in swelling which can even account for the upper eyelid ptosis.  For this reason, I recommend being patient and assessing your eyelids at 2 months.  To give you perspective, we generally let eyelids heal 6 to 12 months before deciding if revisional surgery is necessary.

Some
initial asymmetry is very normal after eyelid surgery. This is because each
side may heal at a different rate and experience different levels of swelling
that makes comparison at 3 weeks difficult to gauge accurately. You should give
your results about 3 months into the healing process before you have an idea of
how your final results will look, although it may take 6 months or more to
completely heal after eyelid surgery. If you still have concerns between the 3-
and 6-month mark, definitely check back in with your surgeon.

A difference between the eyes at 3 weeks is not unusual following blephroplasty.  When having surgery, incisions are made and swelling will make the 2 sides appear different.  Until all swelling and post-operative recovery is complete, you will not see the final result.  Give it a bit of time and follow your doctors directions.