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The chances of having stillborn child cannot be predicted. If the cycles are still anovulatory, then you will require help of ovulation inducing drugs like Clomid to help you getting pregnant. You can start with trying for pregnancy after 1-2 months of taking Rubella vaccination, it usually does not lead to any complications. You can consider having a karyotyping test done to rule out any chances of chromosomal anomalies that could have resulted in stillbirth. It will also help you to know if any further risks are present with future pregnancies.
Discuss your pregnancy plans with your gynecologist and go ahead with the tests suggested before you go ahead with pregnancy to see if any underlying risk is involved.
Take care.