Random mid cycle spotting? Please help :(

I’m a bit worried so just want to check if anyone has experienced anything similar. My period ended a week ago. A few days after it ended I noticed my vagina was a bit sore/itchy, I had thrush-like symptoms and my discharge was slightly off (not cottage cheese but flakier and thicker than usual). I took a Canisten oral capsule on Saturday and this has now appeared to clear up completely.

Yesterday (Tuesday) I had sex with my boyfriend for the first time since this. Everything felt completely fine during foreplay and the sex was nice, however it did feel slightly sore (in my head this was due to slight dryness and the fact I’ve not had sex for about a week due to period and thrush).

Today (Wednesday) I have noticed some light spotting in my underwear. No pain or anything so I assumed maybe just a tear from the sex or something. But I’ve just been to the loo and wiped and there’s now a decent amount of blood? I’m a bit concerned because this does not seem normal? It can’t be an STI as I only ever use condoms but I honestly have no idea if this is a sex injury, reaction to the thrush, I literally don’t know. Any help or thoughts at all would be really appreciated. I feel completely fine in myself so no clue why this has come out of nowhere :(