I know this post and your reply is a couple of years old, but I had to respond when I read your story and the others. In fact, I burst into tears.
I have been experiencing almost identical symptoms for nearly 7 years now. Every month directly after ovulation, I experience these uterine contractions (that’s what I call them, as they’re worse than just “cramps” and I can feel a bearing down. They are triggered predominantly by lying down and similarly to you, they wake me up hourly, almost like clockwork, at night for approx 7 nights. They’re also triggered by sometimes standing up after having sat down for an extended period, and orgasms.
Doctors dismissed me over and over and finally I pushed for a laparoscopy, they found “minor endo” and ablated it, and absolutely nothing changed. I am told the only course of action would be hormonal birth control (which I stopped taking a couple of years ago for various reasons and do not wish to repeat the experience)- obviously that is not treating the cause, only covering up the symptoms.
Whatever this is, it has devastated my life.

I cannot express how shocked I am to find this thread after years of googling. Would love an update if you have one and are up to sharing. Otherwise, I wish you and everyone on this thread well.
We need more research, more support, and more doctors listening.