HIV Prevention :: Positive Symptoms But Oraquick Negative

I just want to start by saying I'm an 18 year old female and have made some mistakes. In mid July(almost 5.5 months ago) I had brief unprotected sex with someone I did not know (huge mistake). It was less than 30 seconds and he did not ejaculate inside me. I felt fine until around October where I began to get worried about having an STD. I went to the doc and they cleared me of any sti but would not do any blood work because I had tested negative 3 months ago. I tried to explain to them it had been exactly 3 months since the encounter so I wanted to be retested but they refused, even though there is a lab on site. So I went home and in November bought an oraquick oral swab test at Walgreens. At 127 day past the encounter I took the oral swab and it was negative. I was eating a little before the test so three days later I bought another at 130 days and it was also negative. After this I felt way less anxious and I was able to enjoy my thanksgiving and felt like my normal self again. About a week later I feel a swollen lymph node on the side of my neck. It's still there, and not painful. No sore throat no fever. I seem to be experiencing loose stools though. So 141 days post exposure I took another oraquick test and it was negative. This time I followed the instructions to a t. Still worried about lymph nodes took another at 147 days and it was negative as well. I just can't relax because of the swollen lymph nodes. The reason I haven't been back to the doc is because I go every 3 months for a depo shot. My next appointment will be 6 months after encounter and any blood work would be definitive. I know this is a long post, but I can't help it I feel so anxious and depressed. Is there any way these tests are not picking up the antibodies? Why swollen lymph nodes if I haven't been infected.