Receiving oral sex is zero risk for HIV, so I'm not sure why anyone prescribed PEP for that event. However, the PEP will offer you protection from your event last night. Discuss this event with the doctor who prescribed PEP in case they wish to extend the PEP prescription to cover a full 28 days post-most recent event.
No idea why you puked. Could be the PEP, could be related to anxiety.