Hallow Dear, I shall give you some scientific information while resolving your query. Usually, it takes about 5-6 weeks after abortion to resume egg release again. So sexual intercourse immediately one week after the abortion is most unlikely to result in pregnancy. During the bleeding phase of menstrual cycle, the egg is not released and hence the chances of pregnancy are unlikely. The blood clot she passed could be either the incompletely passed products of conception or heavy bleeding retained inside. Infection also may cause heavy bleeding. She had intercourse while bleeding, so the chances of infection are very high. Moreover, I would like to advise her not to have sexual intercourse during bleeding; otherwise, there is a great risk of infection. Blood is a very good medium for bacteria to grow. If she does not want pregnancy so soon, she should use some reliable birth control method like intrauterine device, birth control pills or condom. Now even ladies condom also are available. I hope I have resolved your query to your satisfaction.