Are you a guy or girl?
If you are a guy then I have no idea but if you are a girl....hormones. It is typical for women to have those exact symptoms just before or around their periods. If you are a girl with a pouch then those symptoms are felt in your pouch and it makes it worse.
If you are not a girl then look into what it is you do or don' do at that time of the month on a regular basis.
Some people react to travelling others to weekly meals eaten at specific places (Chinese on Fridays or Mexican food the 1st Tues of each month?) or binge eating or drinking...
Specific events of sports can do it to you too if they are recurrent.
Can you give me a bit more info?
Sharon