Hello and welcome to Healthcare Magic. Thanks for your query.
It is possible that you could have strained or pulled a muscle in your abdominal wall. Whenever you cough
or blow your nose or strain to pass stools, the abdominal pressure increases, thus transmitting pressure on the abdomianal wall. This could be that cause of the pain when doing these activities.
I don't think you need to be worried about this. With rest, the muscle strain
should greadually get relieved and the pain should suside. I would suggest that till then, you avoid strenuous work like bending down and lifting weights, etc.
Wish you all the best.
Dr. Jonas Sundarakumar