I had rhino/septum surgery on February 12, I have mucous. My surgeon told me I couldn't blow my nose.

It is common to develop excessive mucus or have residual blood clots in the nasal cavity after a rhinoplasty.  First, it is always more prudent to adhere to the directions of your plastic surgeon.  In my practice, I do not place any packing or splints inside the nose after rhinoplasties which in my opinion is much more comfortable for patients.  I often recommend a saline nasal spray to help break up mucus after the surgery.  You may ask your surgeon if this would be helpful for you.  Good luck and be safe.