Does asprin cause a miscarriage? if so how much does it take to cause it? is it a certainbrand? ia tbis a myth?

Maybe: A recent study suggested that taking an anti-inflammatory prior to conception may be associated with increased risk of miscarriage. Aspirin is sometimes prescribed to prevent miscarriage in certain situations. From the way your question is worded it seems as if you may be trying to treat yourself to cause a miscarriage. Do not do so. See your physician for supervised treatment.