Ok, you're not going crazy! Take a breath!
Firstly, I'm sorry for your mc. It sounds like it was a very early mc? But, it's tough no matter when it happens. I had two early mc's last year, one right after the other, so I feel you honey.
So your cycle can be a bit wonky after a mc, so it's possible your next AF might take a while to show. I think after my second mc, AF didn't show up for two month or so. I actually even called my doctor to ask about it and they said that it was normal but if I reached three month without AF then they would give me a pill to jump start things.
That being said, it is possible to get pregnant again right after a mc and before your next period. DH and I got pregnant after my first mc last year (which unfortunately was also a mc). Did your HCG levels drop back to 0 after your mc? (Or, have you had a negative HPT since?) If you're concerned about being pregnant, I would say to give it a few days, maybe a week and then test again. When you're pregnant, your levels double every 48 hours. So if you are pregnant, your levels should be high enough for a positive in a week. Otherwise, you'll just have to wait it out. As with anything, you can always give your doctor a call to discuss your concerns. Hope that all makes sense and hopefully help!