hello Sir
you have done CMIA test after 4 weeks of window period and being negative you are not infected. however do one more serological test at 45 days of exposure and that is final.
please be informed that some drs have written here to take PEP but it is taken within 72 hours of exposure and after that it is absolutely of no use. so don't even think of taking PEP.
Next Steps
there are other STIS which one may get if exposed with unprotected sex with unknown person.
can further advice you if you wish.
Health Tips
In future use protective barrier to avoid getting STIs and not only
HIV.