I think I had an early miscarriage ?

Okay so my period was pretty late this cycle, usually my period is never late since my cycle is pretty short. I'm not ttc (I'm only 18) so of course I was freaked out. During the 3 days that my period was late I had mild cramps yet no period. Then I started spotting which never happens before I get my period. It was a pink/brownish discharge which I thought was implantation bleeding so I started stressing even more. The next day I started bleeding really heavy and with severe cramps and lower back pain. I started passing clots but the blood didn't smell like period or even looked like it. After the bleeding stopped after 3 days (my period usually last 6 days) I started spotting again which was a pink gooey discharge when i wiped.