Baby choked on milk, she’s ok but I’m nervous

So my lo is 7 months old. Last night at her bedtime feeding she choked on her milk. She’s formula fed (alimentum) and we use a little rice in her bottle per our pediatrician bc of reflux. PLEASE NO HATE. All of a sudden she got a huge belly and turned very red. Then it was like her belly exploded and she puked the milk all over myself and her. It was like 3 seconds and I totally freaked out but it felt like eternity. Anyone else experience this? I’m wondering if it’s bc I am decreasing the amount of rice to try and get it totally out. Could that have been reflux and she puked? The choking part scared the crap out of me. She was fine after but I’m still nervous. Thanks mamas.