Me and my gf had unprotected sex on her CD9, I ejaculated outside but she still take plan B within 1 hour in fear of precm. 5 days later she had period-like bleeding that lasted 3 to 4 days, it was a bit lighter than her usual period. She had taken 5 pregnancy test 14,17,21, 25 and 29 days after the risky sex, all were negative (we use the cheap ones). Does this mean she is not pregnant?