I HAVE BEEN HAVING IRREGULAR PERIODS FOR THE PAST 3 MONTHS.I think I could be pregnant an read that it's possible to bleed every month like a normal period every month and still be pregnant.last month the bleeding was heavy but only lasted for 3 dayS.THIS MONTH I HAD CRAMPS and it is'nt as heavy as a normal period.It started light and was brown.I'm not really sure what to do I been to a doctor and had a negative pregnancy test.Not sure what to do please help!