My girlfriend and I had sex right after her period stopped on the 22nd of August. I did not ejaculate inside of her but just as a precaution I gave her the i-pill on the 23rd of August. After all this on the 27th of August we had sex again but again I did not ejaculate inside of her. Then 2 days later she started bleeding and she said it was like period blood very dark but more then spotting and less then a normal period. She is still bleeding the same for 2 days. Is this withdrawal bleeding from the I-pill or implantation bleeding or breakthrough bleeding. Is this a sign of pregnancy?