Help please

Hello ladies.

So I am on bc. And have been taking it like I’m supposed to.

But , for two days now , every time I pee it burns. I figured out to just drink a lot of water and pee to clean it out. But also along with that , when I wipe it’s old brown blood.

With the burning while peeing and old blood , my vaginal area does itch. I can’t look it up on google otherwise I’d stress myself out thinking I have an std. someone please help