halacha - For those who say the b'racha before lighting Yom Tov candles, when do they say shehechiyanu?

I was taught to say the b'racha on lighting yom-tov candles after lighting, just like for Shabbat, but I understand that some say the b'racha first on yom tov. For those who do and say shehechiyanu at candle lighting, is the sequence: b'racha, light, shehechiyanu, or b'racha, shehechiyanu, light?

An argument for the first would be that we don't make an interruption between a mitzvah and its b'racha. An argument for the latter would be that we want to tie the b'racha that ushers in the day to the one that gives thanks for reaching it, so maybe there shouldn't be an interruption there.