1. Dose and duration of X-ray exposure decides the chances of abnormal Ovum/Rgg in the ovary.
2. The cureent month Ovum/Egg in the ovary has been selected 3 months back only. So if pregnancy happens this month, the egg was selected 3 months back which has nothing to do with ur today's X-ray exposure
3. Main thing here is: there are studies showing that there is 25% more chances of pregnancy for next 3 months after HSG as tubes are flushed.
Next Steps
You can try for pregnancy in the same cycle and chance for positive result will be there for next 3 months.
Health Tips
Take Folic acid preconceptional to prevent any major anomalies in the baby.