Pregnant or Not

Patient: To whom it may concern.Me and my girlfriend had unprotected sex sunday morning aprox. 01:00am i pulled out and came outside of her, but not sure whether there was sperm that went in although we sure majority of the sperm outside she got her periods sunday afternoon as it was due anytime from sunday anyway. I bought the morning after pill and although she got her period she took the morning after pill the sunday evening. She discovered that she had heavy blood flow sunday when she got her period and monday during the day, by monday late afternoon she discovered that the blood is dark in colour and by the evening no flow nothing.Can someone please give me advise as to what the cause of this could be and are we in any danger in terms of her being pregnant and will she her periods again this month?