So, on the first day I was heavy, 2nd day I was some what heavy, and then on 2nd day at night, it was light, and on the 3rd day, it got lighter. Now, the 4th day, it is super light. Couple days before I had my period, I pee'd a lot, was thirsty, tired, and hungry. Does this mean I had a miscarriage? Am I pregnant? Or what am I?

None of your symptoms 'mean' anything definitive, nor do dozens of others. Menstruation and pregnancy are too similar. You can be sick with something totally unrelated, you can have hormone fluctuations for any or no reason, you can have a miscarriage and not even know it.
Plus, it sounds like you assume that all women have periods of more than 4 days? Not so. The range is huge, and we all fluctuate over time and especially as we age. (I started gushing for a week and went down the next 37 years to 2 days of light spotting.)
Are you pregnant? Probably not, but even that is uncertain. Some women do bleed after conception.
Were you pregnant? You will never know.
If your wish is to not be pregnant, then worry will affect your cycles too. Getting on the pill or patch is better than worry.