Thanks for your consult at DoctorSpring.com.
Bleeding after having sex is referred to as post coital bleeding, and is not normal, as you rightly surmised. It could have a range of causes.
The commonest is some kind of lesion on the cervix - such as a polyp, an erosion, severe dysplasia of the cells on the cervix.
Given your history of HPV, this kind of diagnosis of a lesion on the cervix seems most likely to me. However, what is puzzling, is that you say you had a pelvic exam ( and I assume a thorough per vaginum and per speculum exam was conducted ) - and most, if not all, of these lesions would definitely show up on pelvic exam.
In addition to a pelvic exam, a Pap smear is a must, alongwith a colposcopy and a hysteroscopy if required.
Colposcopy is internal evaluation of the cervical canal and hysteroscopy is internal evaluation of the interior of the uterine cavity, both using telescopic lenses, often picking up lesions missed on a pap smear, or providing additional information.
The next common group of reasons is of course infections - you should have a thorough pelvic exam, culture and swabbing if any suspicious discharge or evidence of infection is present, and yes, screening for STDs, Mycoplasma Genitalium being a leading one these days, and implicated in post coital bleeding, so yes, you should get tested for that. It wont show up on a pap smear.
Hormonal imbalance leading to an extremely friable and delicate vaginal lining, that easily injures, cracks up and bleeds during intercourse is likely - again this has a typical look that would show up on internal exam.
If all of the above work up is normal, then it raises the possibility of maybe trauma during intercourse leading to bleeding.
I hope this answer helped you. Please feel free to ask further follow up questions.
Patient replied :
thank you for your answer. there are no signs of infection and it is hard to find a lab that tests for mycoplasma. are you sure this will not show up on a pap smear?
Pap smear does not identify any infections specifically, just points to non specific infection in the cervix, and only detects HPV if present.
You are right, routine testing is not available at labs commonly for M. Genitalium, it is available only at research centres.
Instead of going for expensive testing, you can treat yourself empirically for the infection, Azithromycin is commonly given for most STDs, and is effective against M. Genitalium too, it is better to take the treatment instead of opting for the testing.