Pregnancy after surgery..

So I recently had my gallbladder removed due to gallstones from my previous pregnancy with my daughter. My husband and I are wanting to try for another since our little girl is almost 2 now. I had my surgery January 20th(I ovulated this day too) well I was expected to get my period this past Sunday but nothing. I'm 5 days late and I KNOW I am not pregnant because I was in the hospital during the times of being fertile and ovulating. I'm sure my late period is due to the amount of stress my body just went under. I've already spoken with my Dr about trying again and he is fully okay with it. Question is since i missed this months period when should I try? Should I try my predicted ovulation date for this next time or wait to see if my period comes back? Sorry for this being LONG 😬