The groin pain can be related to hernia but can be confirmed after examination. As far as far as your periods are concerned, you are in premenopausal menopausal age so it might be due to that as it is quite possible that it is due to menopause you have irregular periods.
Next Steps
Consult a general surgeon to examine and diagnose your groin pain
Health Tips
Don't lift heavy. weights till you consult a doctor