When you are cycling it could be gas causing the pain and it may just be your muscles spasming.
or Gall bladder attack ..
It sounds like acid reflux - I get the same thing. Could there be a connection with your monthly cycle - ie fluid retention causing pressure?
The other thing I have noticed is it can flare-up if I do a lot of cleaning - like cleaning windows or mopping floors - just some suggestions - hope you feel better soon