Hello I thought I started my period about 4 days ago but I've been only bleeeding at night and its not really red it's a light pink with a heavy brown I'm on birth control I get the shot what could it be?

Birth control is supposed to regulate your periods, but sometimes it just makes them weird. I wouldn't be worried.

OK it's me again here's an update. It's been 18 days still bleeding every now and then but mainly only when I pee. My family has a history of bladder cancer and cervical cancer.. The health department where I got my shot isn't concerned about it they didn't even want to hear about my family history. When my dad and grandma were diagnosed they also peed blood. I also have kidney problems and galbladder problems in my family.