Take another pregnancy test. If your period doesn't turn up by mid-October, see an ob/gyn. There are many reasons for your period to stop besides pregnancy.
July 4 I started my period lasted till the 11th. Spotted the 15th till the 18th then spotted again the 19 and stopped that night. Took test and its negative and now it's 09\07 and no period. Why?
If you've had sexual intercourse during this time, there is a chance you are pregnant. You didn't say if you did or not. If you are young, it's normal for your period to be a little irregular. However, if you've had sex, there is a possibility that you are pregnant. You need to take another test.
If you have not had sex and your period hasn't started by October, you need to see your doctor to see what's going on.
If you've had sex, haven't had your period in a couple of months, are getting negative results on an over the counter pregnancy test, see your doctor. Good luck.