Hi and thanks for the query, the possibility of pregnancy shall depend on a series of factors. First if the condom was put appropriately, the chances of a pregnancy shall then be relatively very low. Secondly, if you were during your fertile period or not.,It might be necessary to carryout a pregnancy test in case you not see your menses normally. The yellowish vaginal discharge cannot actually be attributed to a pregnancy. If it is foul smelling, it supportive of Trichomas vaginalis infection. Other pathogens could also be involved. I however suggest you consult you primary care physician for a proper evaluation and advice on appropriate contraceptive methods adapted to you. Thanks and best regards, Luchuo, MD.