Hi and thanks for the query,
The commonest cause of lack or delayed periods in a female of reproductive age is pregnancy
. Considering the fact that you had risky sex, this increases the chance even more. Its worth noting that the removal of the penis before he came, called the withdrawal method is one of the most ineffective birth control methods. I suggest you get a pregnancy test done. As for the yellowish discharge, it would be interesting after excluding a pregnancy to carry out a vaginal and cervical swab, cultures and anti biotic sensitivity tests to exclude a possible infection. Foul smelling yellowish discharges are usually associated with Trichomonas vaginalis
. However, in this case, excluding a possible pregnancy is the most urgent and important step.
Thanks and best regards,