Hiv could infect you the 1st time or the 1000th time
Unprotected vaginal sex of course allows the chance hiv to infect the person
But remember hiv is hard to get anc plus the other person actually has to have it
If you have had unprotected sex, then you have a risk. Not going play the 'how risky' game . A risk is still a risk. Take an ag/ab test at 6 weeks followed by a simple ab test at 12 weeks to conclude.
Moving forward, if you are going to e sexually active outside a monogamous relationship, you've got to learn to protect yourself. Insist on condoms everytime. They work!