I had a sex without condom with my gf 6days ago.but she ate a pill.2days ago she had a period.her bleeding is way less than before.is she pragnent?

Check a test: The easiest way to find out and the most definitive way is to check a pregnancy test. If your only contact/intercourse was six days ago though, the test will not be positive yet even if she is pregnant. Don't want to assume anything, but pretty sure you have had intercourse prior to six days ago too, condom or not, check a pregnancy test.