Is it true that aspirin does not help women to prevent a heart attack? just read that in several sites online and im worried

Yes and no: Recent large studies following women who took low dose 81 mg Aspirin over several years found that it was ineffective in preventing heart attacks but did reduce strokes in woman over 65. At the time of a heart attack or suspected heart attack it is strongly recommended that both men and women swallow two full crushed aspirins which can help dissolve blood clots in the coronary arteries.

Doc: Asa does not do the job alone. Risk factors are important such as cholesterol, blood pressure and so on... Check with your doc.