Natural ways to start AF

Nira • Wifey.Mommy.Happy
AF is due Friday, if I don't get a BFP or AF by Monday, I need to get AF to start naturally lol.
I haven't had a period since June (due to mc in July), and if I don't get pregnant or AF in 3 months my dr wants to put me on birth control (which I'm really against).... 
Help!!! How can I make AF show up?? (Or just send me lots of baby dust ;) )