If she gets her period she's not pregnant?

Me and my girlfriend had sex unprotected May 17th but I didnt ejaculate inside of her. She took plan be the next day and then spotted a bit about 4 days later, had a normal period for 2 days and then spotted again the fourth day. Then she started birth control June 5th. Today she told me she started lightly spotting, the first day of her white pills (alesse birth control). Thursday we got sexual but I didn't do anything with my penis except put it in briefly unprotected (2 secs tops) and ejaculated on her back (some on my hand but no where near entering her vagina). If she gets a full period starting tomorrow or soon, shes not pregnant right? She had a negative pregnancy test 17 days after the sex and another negative test 30 days after.