late period

I was supposed to get my period around the 22nd (give or take a day). didn't happen. I don't feel any different except that my nips feel a little sensitive when I'm not wearing a bra. I went to the doctor on the 18th and had my yearly physical (including blood work and a urine test) and the doctor didn't say anything. I also started using ylang ylang twice a day, but I don't know if that would effect my period. any suggestions?