Need some opinions!!!?

hi guys, I have polycystic ovaries and have just recently found out i am pregnant! All happened naturally but with my periods being all messed up I don’t know how far on I am..went for an internal scan today, and the nurse said she couldn’t see any sign of pregnancy inside my womb, she then checked my ovaries which were normal, then a couple of minutes later she said she could see a millimetre dark shadow in my womb?  Iv had blood tests done and have to go back Friday for some more to check my hormones have doubled? Do you think it’s because its too early to see anything on the scan or should I be worried? Help