What should one do to make periods come early, does eating papaya makes it happen?

m 23 yrs old pls tell me i had an abortion done earlier in 14th March 2011 n my periods started from 16th March 2011 and from there onwards my periods began on 2 nd of every month but this month it has not come please tell me what to do i am worried a lot and i dont want to get pregnant now please help...