I had a cystectomy on the 10/10/17 did not bleed after the procedure & still haven't got my period.when should i get my period or go back for a check?

Periods: Pregnancy test is required urgently if have been sexually active within the last 4 weeks. May find that the physical stress of the operation itself can interfere with regularity of periods but would still be worth a check by the doctor for consideration of other less common causes if pregnancy test -ve and period not arriving when due.