im 20 years old and way under weight so when i went in to be put back on birth control my doctor put me on the depo shot i have had nothing but problems since then constant uti's and no periods(since last october) well yesterday i started cramping worse then i ever had and i went to the bathroom and there was blood but it was black and clotted no actual period like blood i have an appointment to see my doctor next monday but im worried that i should go in before that.