Hi.
Thanks for your query.
Noted your history of being on birth control pills for a long period with normal periods except now that you have missed for 3 days. You have lots of gases, feeling of gas bubbles, passing more gas than normal which usually you get before ever period. Recently lost 5 pounds but gained muscle mass.
I do not think this affects the periods.
It is possible that due to
stress or
anxiety or for unseen reasons this can occasionally happen.
I would advise you the following:
Not to worry about.
Wait and watch, the period may be in the offing.
It is possible that you may be practicing exercises hence loosing the weight and still gaining the muscle mass, this does sometimes change the internal
hormonal cycle.
If there is problem with stool, get it checked and if infection is present, get treated properly.
Do not take protein or such supplements as they can cause al such changes that you have noted above.