postpartum bleeding and pregnant..?

I gave birth to my miscarried twins on the 11th but miscarried them 2 weeks before that. I had my postpartum bleeding like usual for about a week and then when it slowed down, my bf and I had sex more then once and then my bleeding stopped completely after that. Well ,a couple days ago we had rough intercourse and I'm bleeding medium heavy now. I also don't know if I am pregnant again but every test I take, the lines are getting darker. What do you all think about the bleeding and maybe being pregnant again?