My GF and I had oral sex on January 28th 2016, however I just inserted her for around a second without any ejaculation. She had period flow from Feb 6 to 8 and again from Mar 6 to 10th .. should I still worry about her pregnancy. No period delays here.
Also we did regular urine tests from 6 to 18th Feb, all negative and blood HCG level on 26th was 0.1 miu/ml.