I took ella (ulipristal acetate) on day 11 of my cycle. i usually ovulate on day 14 or 15. i am scared that ella (ulipristal acetate) won't work because its a new product. can i take plan b?

No need: Ella (ulipristal acetate) is at least as effective as Plan B which must be taken within 72 hours after unprotected imtercourse. The greater concern is that you get a reliable method of contraception so that this doesn't happen again and use condoms to prevent STDs.

Not advised . . .: If you took Ella (ulipristal acetate) within 5 days of sex. It prevents pregnancy by suppressing your natural progesterone and delaying ovulation. It is not recommended that you take Plan B too, as that contains progestins which may interfere with the action of Ella (ulipristal acetate). If you had been taking BCP's and missed doses, use alternate protection as well until your next cycle. Neither is recommended for maintenance BC.