Serious miscarriage question?

So I thought, really thought, that I was pregnant this month. But my AF came. And oddly enough it came almost a week early which NEVER happens. It’s always right on time or late. I’ve never had it early in my adult life. Anyway, so I started and it was so painful I was sick to my stomach. It lasted on 3 days (which is also abnormal because it normally lasts 4-5) and it was super heavy day one but basically spotting day 2&3. even when I was spotting it was still so painful. I’ve only ever been pregnant once and it was thankfully successful. I’m just curious because I’ve never experienced on, if this could have been a miscarriage? Please don’t take offense, I’m not trying to be rude or hurtful or anything. I’m just extremely curious and wanting to make sure I don’t need to go to the doctor.