I am looking for help / advise on post coital bleeding. 

I am 34 years old and otherwise healthy I am on no birth control. Periods are regular and pretty normal - only issue I have ever really had is pain in my left ovary during ovulation. I was advised previously that it was enlarged, but nothing to be consered about when I was younger. 

However I have experienced 3x extremely heavy bleeding after (during) sex with no real cause identified. For reference, I have not been having regular intercourse- 3 / 4 times in the last maybe 10ish years I have had intercourse has resulted in heavy bleeding. 

The first time, I just thought it might have been a tear or something, and genuinely thought nothing of it. 

After the secomd time, I made an appointment with my GP. They examined me, but found it hard to see as I was still bleeding (few days after) so was referred for ultrasound. I was due my smear at that point, so had that, alongside STD test and both came back clear and normal. A week or so after, I thought I may have passed something like a polyp or fibroid, as a smallish (pinky size) piece of flesh came out of me. When I phoned the GP again, they advised they would rush my ultrasound and had that appointment about 2 week later and was told everything looked good. No other follow up was needed. 

Last instance resulted in hospitalisation for severe bleeding to which I needed IV iron (my hemoglobin dropped by 30 points from admission - resus had actually ordered me blood thinking I would need a transfusion and thankfully did not). It was quite traumatic as I bled out in public and was unable to get an ambulance. Ended up passing out in the A&E toilets due to the blood loss and became quite sick as well as being tachycardic. They obviously managed to stop the bleeding and I had a few vaginal exams during my stay but they were happy enough to discharge me and to follow up with gynae 3 months after to give my body time to heal. 

I've had a few follow up appointments at the hospital. Had a speculum exam to which the doctor had said he found eptrocian and that was likely the cause of the bleeding and he refered me for a colposcopy, I had my appointment a few weeks ago, but was told everything looked healthy during appointment so was officially discharged. Smear was 3 years ago and fine, so they confirmed I would next be seen as usual in 2028 when I would next be due. 

I am still awaiting a final abdominal ultrasound appointment as a "last check". But after having 2 previously, and my last one (2 years ago) being fine - I am not expecting anything to come of the appointment. 

I am now at a loss of what to do, where to go, and whether there is anything else I can get checked or tested for- and of course, I am very worried about it happening again.