chemical pregnancy or weird period?

Okay so I had a miscarriage back in February, got my first cycle last month and it was like any other normal period for me. This month, I was due to start the 18, but I ended up starting my "period" yesterday....but this "period" seems very strange to me which is why I'm wondering if it was a chemical pregnancy. I usually have a heavier flow the first day but it quickly lightens up, I usually never even soak my tampons. Yesterday I woke up with cramps and had already bled in my underwear. I continued to bleed very heavy and still am. Like this morning I woke up to change my tampon, it was full and when I pulled it out blood was like everywhere, leaking out of me even. Has anyone ever had this happen? How do I find out for sure if this is just a bad period or a chemical pregnancy??