Period or not?

On May 29th- June 4th I had a period. On July 29th_31 I had a period but it was a way lighter flow and less than a week long but I was already days "late." I spotted a few days before then stopped before my period. A week before I had really bad constipation, that problem was resolved. Then last week a had severe stomach pain for about 3days. It didn't quiet feel like cramps.

I can't figure out when my period is supposed to be for August. I think I'm three days late.

I've taken 2 preg tests and both say negative.