Going completely crazy!

So I got my BFP on Friday, just one day shy of 4 weeks pregnant— super early, I know. I tested twice more that day and once more the next— all positive. I’ve been cramping since last Tuesday, so I seriously thought AF was on her way. Today I’m cramping and have had some scant brownish spotting, so I headed over to the OB, completely hysterical. It’s still too early to see anything on sono, but my urine test was still positive. They drew blood today and I go back Thursday for more. The OB said it could really go either way at this point because it’s super early— I could either be gearing up for a pregnancy or it could be a chemical. Waiting is awful. With all this cramping, my hopes are at an all-time low. I wish I would just get the worst over with already.