Need help tell her parents !?

well this what happend my gf went on a trip to help her aunt cuz she was sick with her friend and i had to work so she sayed there for 7 months and before she went on the trip we had sex and she come home and i pick her up and freaked out then she told me i was so shocked but she said she didnt call cuz she thought i was ganna leave her but im not how should i tell her parents btw im 19 gf 18