made a stupid choice even in life ,went to a party last night and my friend into a csw ..she took her to her place and he had intercourse (condom protected ) while we having sex i felt something different and when i pull back i noticed the condom was inside her ..and my bare penis exposed to her fluids for more than 2 to 3 seconds ...im really scared and asked her about the stauts, she said he lastly had sex with an old man without using condom !!!!! ...im almost shocked ...what if that old man gave her hiv? and it happen only 10 days back , if she infected her viral loads could be high enough during this 10 days post exposure , so that i can easily infected rite ? ....i need experts advice , do i need to take pep?