Ok my boyfriend and I had unprotected sex on August 13 and on the 14 I started my period the next day and it lasted six days and it always last for 4 days and my mother bought me pregnant test like the second week we had sex and it said not pregnant but it's now the 11 of September and my breast are hurting and getting headche..,. Am I pregnant?

Most likely PMS as the early symptoms are similar.

Is your period late?

Testing before you miss a period is just a waste of a test.

Wait till the time for your next period, if you miss it, then test a week after it is late.