Ladies - spotting/bleeding after exercise?

I found a very old topic on this but no updates and replies so thought I'd start a new one. 

I am 45 and have been running for 3 years. About 6 months ago I started doing longer and harder runs and at about the same time I noticed that I'd spot after a hard run or gym workout. It would normally happen bang on ovulation day but sometimes a bit after this too. I have had a smear test, blood tests and a swab done and nothing was found. Just waiting for an ultrasound scan next week but my GP is convinced it is perimenopause and thus related to hormones, etc. My periods are painless but quite heavy too and apparently this is also a sign of peri. I have also read about anovulation bleeding and think it could be to do with that but either way, it really gets me down and it's making me not want to go out and run. This is so depressing as I love keeping fit. Anyone else with similar experience?