Feeling frustrated.

Ellie 🤱🏼👩‍👧‍👧
So last month I had a chemical pregnancy otherwise known as a false positive. I was gutted so was my partner as we both want to have a baby. 
I am still technically on the depo injection. However was informed my body had been rejecting. Yesterday I woke up went to the toilet and there was blood. Needless to say I got excited as thought it could be a period. 
Not all. Took an hour and it was spotting. It had changed into a brownish colour with clots. 
Has anyone had this on the injection? Or close to when they had a normal period after the injection? I honestly just want to try for a baby' it's starting to really get me down. I've got proper period pain cramping. Any answers would be great!