burning after sex

I did so many new things during sex and have no idea what caused the burning:
I was spotting so I put in a u cup so he couldn’t tell (I bled through anyways)
We used new condoms (same brand, thinner, more lubricated)
I just got over a yeast infection (I’d think my period flushed that out though)
Any clues? & how could I stop the burning pee