Really pleased your all ok after your op and recovering nicely - I can see what you mean about them not being able to pinpoint one real certain cause of it, which you could then try to do something about, but that does mean, there is also no real reason why it won't happen, so a better outcome I think.
Interesting to hear what you say about the spotting before period if your progesterone levels go up more - thank you for mentioning that. My periods used to be fine and for the last 6 months , I thought my hormones were messed up as I turn into a physco just after ovulation when I think progesterone should kick in and I start spotting 6 days before period is due each month.