Could I be pregnant? Or maybe yeast infection? Or normal?

So for the last two ish days I’ve been having a very subtle burning sensation down there. It’s barely noticeable, mostly after I pee. And I also noticed I had some blood everytime I wiped, also barely noticeable it was just slightly pink and barely there. But tonight I noticed I had some thick light brown discharge in my underwear. I asked my mum about it and she said it’s probably normal since I’m on the pill and that could cause irregular bleeding between periods. Has anyone else experienced this? Thanks in advance!