Oof, my luck XD

Congrats!
Yesterday I got back-to-back Cyndaquill.
Last event, I got back-to-back Beldum.

...on Gengar raid day, my last 5 raids produced 4 shiny. My raid day ended on a run of 3 straight shiny Gengar

Never had back to back shinys. Didn't get a shiny charmander on its day but when trading came out my friend traded me one for a shiny magicarp he was missing. A month later we both caught the shiny we just traded for

You're not alone, didn't get one either but I don't really care since I was just in it for the stardust. Shinys are overrated anyways

I'm really starting to think there is a moment your RNG hits a sweet spot and you get shinies non stop, kind of chaining shinies. For Pinsir i spent hours searching for the shiny (in a local park which happened to be a Pinsir Nest) and the moment i hit the first shiny i got 4 more out of 10-12 encounters. But shiny Ponyta? Not even one although my second wild Cubone during the event was a shiny. I got 6 shiny Cyndaquils but just 3 beldums (and 2 of those in the last 10 minutes of the CD). It seems if it's your day it's gonna be great but if the sweet spot is not there no matter how many times you try you will get nothing.
Luckily playing with friends makes almost certain that someone will have a surplus of the shinies you miss to trade later :)

Congrats on back to back shiny !!! Once hatched back to back shiny which I thought was going to be to be unbeatable luck, till I got back to back perfect Legendary, yes I’m bragging