Have you taken a test to confirm you are pregnant? You can’t rely on symptoms. You should take a test.
@Amie taken multiple tests
I would go to the ER and let them know what's been going on.if you don't want them to notify your doctor, tell them you don't have one. That way you'll know for sure what it is.
It is possible you’re having an early miscarriage or you may have had a chemical pregnancy and are now having a regular period. Not really going to know without going to doctor to check hormone levels.