Chemical pregnancy

Morgyn

I feel like this is a stupid question but what is the causes of a chemical pregnancy?

I've been trying to convince we found out we were pregnant got really excited went back to the doctors 2 days later as they requested all tests say negative now... The doctor (which I do not like at all and am changing doctors) didn't gibe me any answers at all she pretty much just said keep trying. I'm just kinda confused...

Thanks