Disclaimer: Unless you are the owner of a vagina, the following information will benefit you in no way.
I have been keeping precise track of my cycle and how this pain relates to it. I have been having menstrual-like cramps, that occur only during days 14-21 of my cycle. It comes in waves, about two minutes apart. This will last for up to 20 minutes. It is brought on especially by running, but anytime I significantly exert myself. Not even huffing puffing. I used to think it was the result of being unfit, but I continue to get it despite being in relatively decent shape.
It can come on during the run (/workout) or when I'm walking to cool down. I've never had a baby, but it feels as though contractions might. It's a dull, indescribable pain that leaves me shaking, wanting to go to the bathroom, etc. It takes everything I have to not scream, the first time it happened someone almost called the ER. I'm not trying to sound dramatic--I am used to painful menstrual cramps, but this is in a class its own. When it eventually dissipates, it goes in waves, until about 20-30 minutes after the workout it is as if nothing happened (feeling normal feels like bliss at this point.)
I decided to ask this because today is day 14 of my cycle, so I have identified the correlation! Now if I could just find a way to make it stop.
Oh, and before you advise me to call TLC, unless I'm birthing Jesus, there is a 0% chance that I'm pregnant.