Am I pregnant?

Hi, so my last for sure period was in January 2018. I had a miscarriage in may 2018. Well I still haven’t got a period. So 2 weeks ago I was getting some cramping and then bled very light for 3 days. Which is abnormal for my periods cause they are 5 with a pretty normal flow. Well 3 days ago I started feeling pain in my nipples whenever I had a tight shirt on. Now it’s anytime anything touches them. I been moody. And it seems like around the edges of my areola are darkening. Could I be pregnant? I think so bc the only times my nipples hurt like this was when I had my miscarriage so when I was technically carrying a baby. I also bent over one day and started getting back pains in one spot every time I bent down that day