What Are The Chances Of Conceiving After Taking I-pill Followed By Sex?

hello mam iam a 22 yr old female.last month i got pregnant and had a medical abortion on 15 dec of 5 weeks old foetus..16 jan i again hd sex wid my fiance and ever after insisting he did'nt used a condom..i took an i pill after 4 hrs...my periods are still missing....iam not feeling well at all...i already hve polycistic ovaries....is there any chances of me getting pregnant even after taking an i pill..