Possible miscarriage or late period?

I ended up having protected sex on the 24 of July and didn’t get my period till August 28, Even though I was supposed to have it on the 30 of July.

I had ended up having a lot of back pain and morning sickness a week after intercourse and I believed I was pregnant. Also my period was over 6 weeks late. Around a week ago I was drinking heavily for about 4 days and having 1 meal a day for 4 weeks. (I’m still not ready for a kid and i knew what I was doing) Suddenly I had my period and there was a lot of tissue involved and its heavier than normal. I’m not sure if I just had a very late period or a possible miscarriage. Any insight?