I Had Two Periods In The Months On May. Regular

I had two periods in the months on may. Regular flow on the 4th to the 7th then again on the 30th til the 1st but very light i normaly have heavy periods. Nothing for june and its now july and still no period?? Any ideas?? Ive taken pregnancy test and mostly all neg only had like one or two with a very faint line its almost impossible to see...