What Is The Cause Of Delayed Periods?

hello,
Last month me and my gf doing dry humping and i ejaculate during that and i was on her that time and she said she felt some wetness near vagina. We both were wearing jeans and undergarments at that time,can she be pregnant?
she didnt have period on time this month the period should have occured 2 days before but she didnt have it till now.
please suggest what to do . is she pregnant from above situation?