Welcome to healthcare magic!
You should always use a premium quality condom in modern times because even a burst condom can ruin you. An act that's supposed to give pleasure can cause stress
and become a punishment.
If you are within 5days of pre/post-ovulation timing then take a morning after pill to prevent pregnancy
Taking antibiotics is of no use at present.
If you get any symptoms then you should get a check up and then take proper antibiotic
I think that answers your query.
Still if you have any queries or doubts, please write me back,
I would be happy to solve them.
Wish you a great health!