Hello & welcome,
As you have undergone the tedious procedure of removing wisdom teeth , this swelling or knot like feeling is nothing but post operative effects of the procedure.
This usually happens if infection has not completely subsided.
Or there may be transient bony reaction to the residual infection which is less likely here as location you mentioned is cheek.
If it is Antibioma which forms if pus or swelling is not completely drained even after extraction of the related tooth, then it will take around two weeks to completely resolve.
Maintain your oral hygiene
to optimum. Avoid hot fomentation over the affected area. Use of antibiotic should not be restricted unless asked by your dentist
If the knot persists even after 2 weeks, don't hesitate to visit your dentist & undergo proper clinical examination.