inducing a period?

[https://users.livejournal.com/pretendworld-/]

My last period was November 12th and I assume that I am somewhat late at this point. I haven't had a 'regular' cycle since I stopped taking Yasmin in early August, but my period has come and gone without fail roughly every four weeks. I'm wondering if stress could possibly be the cause of delay? Not sexually active.

I've seen people here mentioning parsley tea as a way to induce your period. Is this something you can buy in a shop? Is eating parsley just as effective? Stupid I know, but I really don't want my period to arrive Christmas moring :(