LATE PERIOD

As of right now I am 9 days late on my period.... Kinda freaking out at the this point. My period is irregular most of the time but never this late. I had unprotected sex on June 20th and I took Plan B within 48 hours. 6 days later I started to bleed, only this time it was lighter but still looked like a period. So my period time rolled around again and it hasn't come yet... I had some back pain and headaches but that was for one day or so. I've been taking vitamin C and Dong Quai to hopefully start my period. Any advice or ideas?