How long after an etopic pregnancy do you have to wait to conceive again?

It depends on your doctors advice. Usually three months before trying to conceive again. If you had a molar pregnancy you should be having regular checkups to ensure that all the prregnancy hormone has gone. As Trisha said you should wait until the doctor tells you it is all right to conceive again. According to the website http://health.allrefer.com/health/hydatidiform-mole.html this may be 6 to 12 months. it is mis-spelled above, try "molar pregnancy" if you google that, you will easily find your answer.