Gynecological issues. In taking breath.

Hi Doctor, we are trying for pregnancy. Period got delayed by 5 days by today and today i tested with morning urine and got negative My periods usually delayed by 3 to 4 days and average cycle length is 33 to 34 days .. This month period delayed but I did test and is negative but I am feeling like my stomach will explode and it looks like 5 month pregnant also so much gas forming..I couldn't touch my breasts as it is more painful from last two weeks .. usually il get pain when I am near to periods but this time it's more than usual. Last time four months back I had a chemical pregnacy and that time I did home pregnacy test at 11 th day after my expected period. Did I do the test early this time? If the pregnancy result is negative ..why my stomach is feeling heavy and difficulty in taking breath..and periods didn't came yet. PLEASE help