Only the head needs protection so trimming is irrelevant otherwise most people would have it from skin cuts. The reason is because hiv is dead in air.
Just take a duo at 4 weeks instead for a conclusive result. Likely she is negative, otherwise why would she pay money for condoms? She only cares about herself, so she bought the condom to protect her, not you and if she could get it from cuts she would have examined your body under a microscope first..
DNA PCR is not an approved diagnostic test. Also, it is not advisable at 2 weeks. It is best taken at 28 days because the HIV DNA is a derivative of the RNA, it takes certain time for production of a double-stranded DNA copy of the viral RNA genome, by 28 days post exposure it's almost always the DNA is integrated out of the RNA and hence this test is said to be optimum at the 28th day.
However, a 4th Generation HIV test - an approved diagnostic test is good by then for a conclusive result.
This test looks for the 'Antibodies' - The body's response to the viral infection and 'P24 antigen' - A viral protein that is found usually between 4 - 14 days post infection in the infected individual's body simultaneously.
IV generation test (P24 Ag and AB 1 & 2 test) taken at the 4th week is conclusive because in an HIV infected individual, if the body has not produced detectable amount of antibodies by that time, it is in process of sero-conversion. In that case p24 proteins would be certainly detected. This occurance is very rare as the average time to seroconvert is 21 days, this specifically takes care of the late seroconversion possibility.
And following the natural course of action, by this time the antibodies are always produced, it would pick up the antibody readings.
I second ANM, the chances of you contracting the virus from this small exposure is very slim. The most important thing is, your partner must be HIV negative. You were only unprotected for a brief moment and it's difficult that way for a female to male transmission.
I personally do not see this to be a high risk. Just take a IV generation test at 28 days, you should be okay.